Ceramic implant placement systems and superelastic suture retention loops for use therewith

ABSTRACT

Using the simplified placement system and method for a tissue graft anchor of the present invention, a surgeon may introduce one or more sutures into a hole in a boney tissue, apply a precise amount of tension to the sutures to advance a soft tissue graft to a desired location, and then advance the anchor into the bone, preferably while maintaining the requisite pre-determined suture tension and without introducing spin to the suture. Particularly preferred embodiments of the present invention allow for the placement of small diameter knotless anchors. For example, the implant placement system may include a cannulated tensioning device having disposed therein an elongate member of a suitably elastic metallic or polymeric material, such as nitinol, that includes at its distal end a loop of material suitable for suture retention. The implant placement system may further include high tensile strength knotless anchors provided with internal drive features that coordinate with torque-transmitting features unique to the driver devices of the present invention.

PRIORITY

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/012,060 filed Feb. 1, 2016, which, in turn, is acontinuation-in-part of U.S. patent application Ser. No. 14/972,662filed Dec. 17, 2015, which, in turn, is a continuation of U.S. patentapplication Ser. No. 14/636,389 filed Mar. 3, 2015 (now U.S. Pat. No.9,226,817 issued Jan. 5, 2016), which, in turn, claims the benefit ofU.S. Provisional Application Ser. No. 61/966,744 filed Mar. 3, 2014;61/998,391 filed Jun. 26, 2014; 61/998,766 filed Jul. 7, 2014; and61/999,405 filed Jul. 26, 2014, the contents of each of which are herebyincorporated by reference in their entirety. This application alsoclaims the benefit of U.S. Provisional Application Ser. No. 62/284,151filed Sep. 21, 2015, 62/387,647 filed Dec. 29, 2015, and 62/389,536filed Feb. 29, 2016, the contents of each of which are herebyincorporated by reference in their entirety.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to the field of endoscopic andarthroscopic surgery and suture anchor systems and devices for usetherein. More particularly, the invention relates to a knotless sutureanchor device utilized to secure soft tissue to bone or a boney surfaceto preclude the need to tie surgical knots to secure the tissue in placewith the device. Specifically, the invention relates to a simplifiedanchor system and method by which the surgeon may introduce one or moresutures into a hole in the bone, apply tension to the sutures to advancethe soft tissue to a desired location, and then advance the anchor intothe bone while maintaining the suture tension and graft position.

BACKGROUND OF THE INVENTION

The use of implants to affix tissue grafts to bone is well known in theorthopedic arts. Common procedures in which such implants are usedinclude, for example, the repair of rotator cuff tears, the repair oftorn ligaments in the knee, among others. In these procedures, a socketis drilled or punched in the bone at the attachment site and a graft issecured to the bone using an implant placed in the socket. The graft maybe secured to the implant by sutures, or, alternatively, an end of thegraft may be placed in the socket and secured directly by an implant.

In rotator cuff repair, implants commonly referred to as “anchors” areused. These anchors occur in two types: conventional anchors in whichthe suture is passed through the cuff after anchor placement, and“knotless” anchors in which the suture is passed through the cuff priorto anchor placement. In the former case, the graft is secured in placeby tying knots in the suture after it has been passed through the cuffso as to secure the cuff in the desired location. Conversely, as thename implies, when using a knotless anchor, the sutures are passedthrough the cuff and through a feature of the anchor such that when theanchor is inserted into the socket, the suture position is secured bythe anchor. Accordingly, the tying of knots is not required. This isparticularly advantageous when performing endoscopic (arthroscopic)repairs since the tying of knots arthroscopically through a smalldiameter cannula can be difficult for some surgeons and, moreover, thereis an opportunity for tangling of the sutures.

Many anchors, both conventional and knotless, are supplied to thesurgeon mounted on a driver—a device that the surgeon uses to place theanchor in the prepared socket in the bone. In the case of threadedanchors, the driver has a form like that of a screwdriver, and indeedfunctions in the same manner. The proximal portion of the device forms ahandle that is grasped by the surgeon. Distal to the handle, an elongatedistal portion has formed at its distal end features for transmittingtorque to an implant. Some anchors, generally metallic anchors such as,for instance, the Revo® Suture Anchor by Conmed Corporation (Utica,N.Y.) and Ti-Screw Suture Anchor by Biomet Corporation (Warsaw, Ind.),have a protruding (male) proximal portion with a cross-section suitablefor transmitting torque (typically hexagonal or square) and a transverseeyelet formed therein. The driver for such devices has a complimentarysocket (female) formed in its distal end and a cannulation that extendsfrom the interior of the socket to the proximal handle portion of thedevice. Sutures loaded into the eyelet of the anchor extend through thedriver cannulation (or “lumen”) and are removably secured to the handleso as to retain the anchor in the socket of the driver. Such anchors arereferred to in the orthopedic arts as “pre-loaded”, meaning that suturescome loaded into an anchor that is ready for placement by the surgeonusing the associated driver.

Other threaded anchors have a socket (female) formed in their proximalends. Once again, the socket has a cross-section suitable fortransmitting torque that is typically polygonal, usually square orhexagonal. Typical of these are the V-LoX™ family of titanium sutureanchors by Parcus Medical (Sarasota, Fla.) and the ALLthread™ anchors byBiomet Corporation (Warsaw, Ind.). The drivers for such devices have aprotruding (male) torque-transmitting feature complementary to thesocket (female) formed in the proximal end of the anchor. These driversmay be cannulated to accommodate sutures that are preloaded into theanchor in the manner previously described, with the sutures being eitherfor the purpose of securing tissue after anchor placement, or for thepurpose of removably securing the anchor to the driver, wherein thesutures are released from the driver after the anchor is placed in thebone and subsequently removed and discarded so as to allow removal ofthe driver from the anchor. The depth of the socket in the proximal endof the implant must be sufficient to enable transmission of therequisite torque needed for anchor placement without deforming orfracturing the implant. As the maximum depth of the torque-transmittingportion is generally limited only by the configuration of the anchor, itis considered to be matter of design choice. Indeed, the implant mayhave a cannulation that extends axially through the implant as well as atorque-transmitting cross-section forming a substantial proximal portionor the entirety of the implant's length. Implants of the Bio-TenodesisScrew™ System by Arthrex, Inc have a cannulation with a constanttorque-transmitting cross-section, and are used with a driver having atorque-transmitting portion that extends beyond the distal end of theanchor, wherein the portion of the driver extending beyond the anchorand a suture loop in the driver cannulation are used together to insertthe end of a graft into a prepared socket prior to placement of theimplant.

Knotless suture anchor fixation is a common way of repairing soft tissuethat has been torn from bone. Illustrative examples of such “knotless”anchors include the Allthread™ Knotless Anchors by Biomet Incorporated(Warsaw, Ind.), the SwiveLock® Knotless Anchor system by Arthrex,Incorporated (Naples, Fla.), the HEALIX Knotless™ Anchors byDepuy/Mitek, Incorporated (Raynham, Mass.) and the Knotless Push-InAnchors such as the Knotless PEEK CF Anchor by Parcus Medical (Sarasota,Fla.). The procedure requires drilling or punching of holes into aproperly prepared boney surface. After suture has been passed throughsoft tissue, the suture anchor is introduced into the socket and driveninto the socket using a mallet or by screwing the anchor into the socketusing a driver device. These driver devices typically resemble ascrewdriver in form, having a proximal handle portion for applyingtorque or percussive force, and an elongate rigid distal portion havingat its distal end a torque or percussive force-transmittingconfiguration. In the case of torque-transmitting drivers used withthreaded anchors, the distal end of the driver typically has an elongatehexagonal or square distally extending portion that, through couplingwith a lumen in the anchor having a complementary cross-section,transmits torque to the anchor. The lumen may extend through anchor sothat the distal portion of the driver protrudes from the distal end ofthe anchor and rotates with the anchor during anchor placement.

Because the suture is drawn into the prepared socket along with theanchor during anchor placement, it is essential that a suitable lengthof suture extends between the graft and the anchor so that when theanchor is suitably positioned within the socket, the graft is properlypositioned. Determining the proper length of suture to allow between theanchor and the graft so as to achieve optimal graft positioning iscomplicated since suture(s) may twist (a process referred to in theorthopedic arts as “suture spin”) during anchor placement, therebyshortening the effective length and changing the final graft positionand/or undesirably increasing the suture tension.

U.S. Pat. No. 6,544,281 to ElAttrache et al. describes a cannulatedanchor placement system having a rotating inner member (which acts asthe anchor driver) and a stationary outer member, wherein the rotatinginner member serves to drive the threaded anchor. The rotating “driver”extends past the distal end of the anchor and is inserted into aprepared socket in the boney surface. A suture loop formed distal to thedistal end of the driver “captures” or “secures” sutures attached to agraft or the graft itself to the distal end of the driver. The distalend of the driver is then inserted into the socket to a proper depth foranchor placement thereby drawing the graft to the desired position priorto placement of the anchor. The anchor is then threaded into the socketto the predetermined depth. This system constitutes an improvement overother commercially available alternatives. However, because the graft orsutures are secured to or pass through the distal end of the rotatinginner (or “driver”), torque is transmitted not only to the anchor butalso to the graft or sutures attached thereto by the suture loop.Accordingly, twisting of the sutures or graft frequently occurs, therebychanging the resulting suture tension and/or the graft position (aprocess referred to in the orthopedic arts as “graft shift”).

U.S. Pat. No. 8,663,279 by Burkhart et al. describes a knotless anchorsystem similar in construction to that of ElAttrache et al. A “swivel”implant having formed therein an eyelet is releasably and pivotablymounted to the distal end of a driver distal portion that extendsdistally beyond the distal end of an anchor. After sutures are passedthrough the graft, they are threaded into the eyelet of the swivelimplant at the distal end of the driver. The distal end of the driverwith the swivel implant is then inserted into the socket. By pulling onthe suture tails, the graft is moved into position and secured byscrewing the anchor into the socket. However, because the sutures/graftare secured to the driver by means of the swivel eyelet implant, thetorque that may be transmitted to the sutures/graft is limited. However,torque transmission is not eliminated since the swivel implant isretained in the driver distal end by a suture loop under tension, whichextends through the cannula of the driver to the driver's proximal endwhere the suture ends are cleated. While an improvement over theElAttrache anchor system, suture spin is not eliminated in all cases,and indeed, cannot be since the suture-retaining implant is mounted tothe driver, which rotates during anchor placement. As such, some levelof torque transmission due to friction between the driver distal end andthe swivel eyelet implant is inevitable.

Other knotless anchors such as the ReelX STT™ Knotless Anchor System byStryker® Corporation (Kalamazoo, Mich.) and PopLok® Knotless Anchors byConMed Corporation (Utica, N.Y.) have complex constructions and requirethat the surgeon perform a sequence of steps to achieve a successfulanchor placement with the desired suture tension and proper cuffposition. The sequence of steps adds to procedure time and createsopportunities for failure of the placement procedure if a step is notperformed properly.

Accordingly, there is a need in the orthopedic arts for a knotlessanchor system that allows the surgeon to establish the graft position,and, while maintaining that position, place the anchor without changingthe suture tension or causing a shift in the graft position due tosuture spin. Furthermore, if the anchor is threaded, placement of theanchor in the socket must occur without spinning of the suture.

If a graft such as a biceps tendon is directly affixed to a bone byinsertion of the graft into a socket (a technique referred to in the artas “bio-tenodesis”), it is essential that the graft be fully inserted soas to be engaged by the full length of the implant. It is also importantthat the position of the graft be maintained during anchor insertion.Further, it is essential that the alignment of the implant (referred toin this case as an “interference screw”) be coaxial, or if slightlyshifted, parallel to the axis of the socket. It is also desirable thatthe sutures used to draw the graft into the socket do not spin or twistduring anchor placement as this may change the position and tension ofthe graft from that intended by the surgeon. In sum, there is a alsoneed in the suture arts for an interference screw and implant placementsystem in which graft position within the socket is maintainedthroughout the implant placement process, and in which suture spin ortwisting is prevented.

Improved implant systems also find utility in the context of spinalfusion surgery, wherein rigid posterior or lateral or anterior elements,either pedicle based, interbody based, or vertebral body based, orposterior element based, are routinely performed, by the placement ofscrews into the bony spinal elements and, through either internalmechanisms or rigid bridging devices, engage into adjacent bony elementsor interspaced to provide rigid fixation. Illustrative examples ofcommercially available spinal fixation devices include, for example,Synthes (Raynham, Mass.), Nuvasive (San Diego, Calif.) and Amendia(Atlanta, Ga.), devices that interlock cervical, thoracic or lumbar orsacral levels to rigidly prevent movement and fuse or allow for fusionof diseased or degenerated segments of spine to prevent painful ordisabling movement. These rigid zones of fixation create zones above andbelow these constructs, which are known as junctional or transitionalzones or levels. There is need in the art for a bracing mechanism thatcan disperse load from the rigidly fixed spinal segments havingundergone prior fusion or fixation, to unfused adjacent spinal segments.Such a bracing device, while not providing absolute rigid fixation butallowing for movement, would provide for bracing of the non fusedsegments while off-loading or reducing the forces that, prior to theapplication of such a device, would have been entirely borne by theintervertebral discs and adjacent bony elements and ligaments adjacentto the prior rigid fixed segments. It is this increased force that ispostulated to result in failure of the adjacent segment.

Suitable bracing devices can be inserted either along the anterioraspect of the spinal segments, the posterior aspect of the spinalsegments, or between spinal segments. Between these anchor devices andthe spinal segments or between the fusion devices and spinal segments,or bridging these spinal segments and fusion devices to intact spinalsegments, either soft tissue in the form of grafts, or with braidedsuture constructs, or with a combination thereof, bone anchors areutilized to insert these tension bearing or tension off loadingconstructs. Such tension-bearing constructs serve to provide a dynamicrather that rigid transition from the fused spinal segments to theadjacent spinal segments. The purposes of theses constructs are toreduce the load applied to the intervertebral discs above and below thefused spinal segments. This transitional loading allows the adjacentmusculature to recover following spinal fusion surgery while protectingthe discs until the muscle has recovered sufficiently, while alsoallowing needed movement at the transitional levels so as to not havecreated another static or rigidly fixed level. In addition, suchconstructs can be utilized to reconstruct spinal ligaments. Suchreconstructions can be performed either independent of, or in additionto rigid spinal fixation or along with intervertebral body discreplacements to help restore normal spinal segment mobility and preserveor protect the constructs.

SUMMARY OF THE INVENTION

A primary objective of the present invention is to provide improvedmeans and methods of attaching soft tissues (i.e., “grafts”) to bone insitu. The embodiments of the instant invention are described hereinbelowas a system and method for producing a matrix of implants for theanchoring of a graft to bone. Any graft fixation system which uses animplant placement system with an optionally cannulated non-rotatingtensioning device (i.e., the relatively fixed “inner assembly”)positioned within a cannulation or “lumen” of a cannulated driver (i.e.,the relatively movable “outer assembly”) to tension sutures in aprepared socket for the placement of a simple one-piece cannulatedanchor are contemplated by the present invention. Illustrative aspectsand embodiments of the present invention in accordance with theforegoing objective are as follows:

In a first aspect, the present invention provides prosthetic implantsand systems for their placement in a target boney surface for theknotless securing of a soft tissue graft thereto. The instant inventioncontemplates a novel placement system including a non-rotatingcannulated tensioning device (“inner assembly”) positioned within arotationally and axially movable cannulated driver (“outer assembly”).In a preferred embodiment, a distal element of the tensioning deviceextends distally beyond the distal end of the cannulated driver. Acannulated threaded implant (or “anchor”) is removably mounted to thetorque-transmitting distal portion of the driver. Sutures placed in thegraft are drawn into the distal end of the elongate distal portion ofthe cannulated tensioning device, which extends beyond the distal end ofthe implant. If a threaded implant is used, the distal end of thecannulated driver preferably includes torque-transmitting features that,together with complementary features formed in the proximal portion ofthe implant or anchor, allow the transmission of torque thereto. If aninterference plug-type anchor is used, the distal end of the driver ispreferably configured to transmit axial force to the anchor, the distalend of which has suitably complementary configuration to enable secureattachment.

In operation, sutures placed in the graft are drawn into the distal endof the tensioning device. The elongate distal portion of tensioningdevice is inserted into a properly prepared socket in the target boneysurface so that the distal end of the tensioning device, with itssutures is positioned at the bottom of the socket. Tension is thenapplied to the sutures by pulling on their proximal ends, which extendbeyond the proximal portion of the tensioning device to move the graftinto the desired position, namely into the prepared socket adjacent tothe distal element of the tensioning device. The desired tension may bemaintained by cleating proximal portions of the suture(s) into slotsoptionally formed in the handle of the tensioning device. The anchor (orinterference screw) may then be screwed, threaded or otherwise driveninto the socket, thereby trapping the sutures or graft between theanchor exterior surface and the socket wall. Critically, twisting of thesutures or graft is prevented by the non-rotating distal portion of thetensioning device that remains distal to the anchor distal end duringanchor placement. In addition, tension on the sutures and the positionof the graft are maintained during placement of the anchor throughoutthe procedure. After anchor placement, the driver and tensioning deviceare withdrawn, removed from the site, at which point the sutures may betrimmed to complete the procedure.

In contrast to the Burkhart and ElAttrache anchor systems, suturetensioning and establishment of the graft position are not accomplishedusing the driver's distal end or using an implant positioned in thedriver's distal end. Rather, suture tension and graft position areestablished and maintained by the distal portion of a non-rotatingtensioning device that extends beyond the driver and anchor distal ends.Because of this, the transmission of torque to the sutures and/or graftby the driver present in the Burkhart and ElAttrache systems iseliminated, along with its associated suture or graft spin.

The system and method of the instant invention provide a simplificationover other currently available anchoring methods and hardware in thatfewer steps are required and moreover the anchor has a simple,single-piece construction. The anchor system is scalable and, due to itssimple construction, may be used with anchors smaller than thosepermitted using other currently available systems. The composition andconstruction in the anchor may be readily modified simply by changingthe material from which it is constructed, by increasing or reducing thediameter or length of the anchor, by increasing or decreasing the wallthickness of the anchor, by modifying the profile of the exterior, or byany combination of these means. All such modifications are contemplatedas within the scope of the present invention.

In another aspect, the present invention provides a method for affixinga soft tissue graft to a target boney surface, the method comprising thesteps of:

-   -   a. providing a placement system having a cannulated non-rotating        tensioning device (“inner assembly”) and a cannulated driver        device (“outer assembly”), wherein the tensioning device is        positioned within the cannulation or “lumen” of the driver        device,    -   b. positioning a cannulated anchor onto the distal        torque-transmitting portion of the driver, over a distally        extending element of the tensioning device,    -   c. producing a suitably configured hole (i.e., “socket”) in a        prepared boney surface at a desired target location using a        drill, tap, punch or equivalent hole-producing device,    -   d. drawing sutures from the graft into the lumen of the        tensioning device,    -   e. inserting the distal end of the tensioning device into the        socket,    -   f. applying tension to the sutures to draw the graft to a        desired position,    -   g. placing the anchor (or interference screw) in the socket,    -   h. withdrawing the placement system,    -   i. trimming the suture tails, and    -   j. optionally repeating steps (c) through (i) as required.

In an alternate embodiment of the present invention, identical in allaspects to the previous embodiment except as subsequently described, thetubular distal portion of the tensioning device is replaced by a rodhaving formed at its distal end a sharpened fork portion. Two (or more)parallel, axially extending tines form the fork, the tines being spacedapart so that sutures may slide freely through the channel(s) formedbetween the tines. An anchor placement system commensurate with such anembodiment is used in the following manner: First, a cannulated threadedimplant is removably mounted to the torque-transmitting distal portionof the driver. Sutures placed in the graft are then positioned in thechannel(s) of the distal fork portion of the tensioning device. Theelongate distal portion of the tensioning device with the suturespositioned within its distal channel is then inserted into a preparedsocket so that the distal end of the tensioning device with its suturesis positioned at the bottom of the socket. Tension is then applied tothe sutures by pulling on their proximal ends to draw the graft into thedesired position. The desired tension and graft position may bemaintained by cleating the suture proximal portions in slots optionallyformed in the handle of the tensioning device. The anchor is thenscrewed, threaded or otherwise driven into the socket by the driver,thereby trapping the sutures or graft between the anchor exteriorsurface and the socket wall. Twisting of the sutures or graft isprevented by the non-rotating distal fork portion of the tensioningdevice which remains distal to the anchor distal end during anchorplacement. The tension on the sutures and the position of the graft aremaintained during placement of the anchor. After anchor placement, thedriver and tensioning device are removed from the site and the suturestrimmed to complete the procedure.

A further aspect of the instant invention addresses the placement ofsmall diameter implants. In particular, the placement of small diameterimplants using a cannulated tensioning device such as presentlydescribed may be problematic since the cannulation in the implantdecreases with the implant diameter. This decrease in the implantcannulation diameter necessitates a corresponding decrease in thecannulation diameter of the tensioning device distal portion. As aresult, the diameter of the cannulation in the tensioning device distalportion may potentially be insufficient to accommodate the number andsize of sutures required for the proper securing of an associated graft.Accordingly, in yet another embodiment of the present invention for usepredominantly with small diameter implants, an elongate element formedfrom a suitable metallic or polymeric material forms a retention loopdistal to the distal end of the distal portion of the cannulatedtensioning device, with the proximal ends of the elongate elementextending to the proximal end of the tensioning device where they areremovably secured. One or more sutures are loaded into the distalretention loop formed by the elongate element. Thereafter, tensioning ofthe sutures and placement of the implant are as previously hereindescribed, for example following the steps utilized in connection withthe previously described tensioning device including a “forked” distalend. After the implant is properly placed, the proximal ends of theelongate element are freed and the elongate element is removed from thesite by withdrawing of the proximal ends. In a preferred embodiment, theelongate element is formed of a nitinol wire.

Yet another aspect of the instant invention addresses the constructionof small diameter implants. The minimum size of threaded metal anchorsthat may be created and their configurations are limited by the abilityof a machine tool to produce them. The configurations of small metalanchors used in, for instance, hand surgery are limited to those thatrequire the tying of knots after passing suture through a graft.Similarly, threaded anchors made of polymeric materials such as PEEK arelimited in their minimum size by the strength of the underlyingmaterial. When these threaded anchors become very small, the ability ofa driver to transmit torque to the implant is limited by the resistanceto deformation of the torque-transmitting features of the implant. Whenconventional (i.e., not knotless) anchors are used, the graft must besecured in position by tying knots on the surface of the graft oppositethe attachment site. These knots are frequently perceptible beneath theskin of the patient and can create irritation for the patient.Accordingly, there is a need for very small knotless anchors configuredfor small joint repairs.

In the course of the present invention, it was discovered that anchorsystems of the present invention that use an elongate wire element asdescribed above may be miniaturized through the use of advancedmaterials having high tensile strengths along with the use of advancedmanufacturing techniques. Specifically, very small knotless anchors maybe produced from ceramic materials using a process known as “CeramicInjection Molding” or simply “CIM”. The tensile strength of PEEKmaterial is typically between 10,000 and 15,000 psi. In comparison, thetensile strength of alumina is generally in excess of 200,000 psi.Furthermore, recently developed materials such as Zirconia ToughenedAlumina (ZTA) by Coorstek Inc. (Golden, Colo.) have a high degree oftoughness in addition to high tensile strength. These materials, beingceramic, do not have a yield point and therefore do not deform underload. The high tensile strength and the absence of yielding under loadof an implant constructed of such ceramic materials allow torque to betransmitted to the implant through features that are not producible bythe machining of metal or that would fail in use if formed from apolymeric material such as PEEK. Thus, ceramic knotless anchors of thepresent invention may be produced in sizes and configurations notpossible using prior art technology.

Accordingly, in certain embodiments of the present invention, the distaltorque-transmitting portion of the driver may also be ceramic, formed byceramic injection molding so as to allow miniaturization of thetorque-transmitting features. In other embodiments, thetorque-transmitting portion of the implant is a laterally extending slotin the proximal end of the implant similar to a standard screwdriverslot, wherein the ceramic material from which the implant is formed issufficient to ensure that the anchor does not fail by fracture proximalto its distal end or by failure of the torque-transmitting proximalslot. In yet other embodiments, the ceramic implant is an interferenceplug, wherein the high elastic modulus and high strength of the ceramicmaterials is beneficial for small and miniature interference typeanchors that are driven axially into a prepared socket. The high modulusand high strength of the materials allows the thickness of the wallbetween the central lumen and the outer surface to be reduced comparedto interference type anchors produced from polymeric materials withoutreducing the compressive force which retains the one or more suturesbetween the outer wall of the implant and the wall of the socket.

An anchor placement system of the present embodiment may also include areleasable mechanism for preventing relative axial and rotationalmovement between the driver (i.e., the “outer assembly”) and thetensioning device (i.e., the “inner assembly”), such means optionallypositioned within the cannulation (or “lumen”) of the driver/outerassembly. In a first condition, used during tensioning of the suture,axial and rotational motion of the driver relative to the tensioningdevice is prevented. In a second condition, used during placement of theanchor, the driver may be advanced axially on the tensioning device tobring the anchor to the socket, and rotated to screw the anchor into thesocket, with the tensioning device remaining stationery so as tomaintain suture tension and prevent twisting of the sutures.

In a particularly preferred embodiment, prevention of relative motion isprovided by a removable key having one or more protrusions, coupled withfeatures formed on the handles of the tensioning device and driver suchthat, when the features are in alignment, engagement by the one or moreprotrusions of the key prevents relative axial or rotational movementbetween the torque-transmitting driver and the tensioning device.Removal of the key allows the driver to be advanced distally and rotatedrelative to the tensioning device. Other embodiments are anticipated inwhich other means are used to releasably prevent relative motion.

In yet another aspect, like the previous in all other respects except assubsequently described, the suture attached to the graft is positionedwithin the distal fork and tensioned such that the proximal end of thegraft is adjacent to the fork, the tension being maintained by cleatingof the sutures on the tensioning device handle. The distal portion ofthe tensioning device with the graft is inserted into the preparedsocket. The anchor is then threaded or driven into the socket aspreviously described, thereby trapping the graft proximal portionbetween the anchor exterior surface and a first portion of the socketwall, and the attached sutures between the anchor exterior surface and asecond, laterally opposed portion of the socket wall.

In a variation of the previous aspect, the graft may be pierced by thesharpened, distally extending members (“tines”) of the distal fork. Thedistal portion of the tensioning element with the graft is inserted intothe prepared socket. Once again, the anchor is then threaded or driveninto the socket, thereby trapping the graft proximal portion between theanchor exterior surface and a portion of the socket wall.

In another variation of the previous aspect, the graft is pierced by thesharpened distally extending members of the distal fork a predetermineddistance from the graft distal end such that when the distal portion ofthe tensioning element with the graft is inserted into the preparedsocket, the proximal end of the graft protrudes above the opening of thesocket. The anchor is then threaded or driven into the socket, therebytrapping the graft proximal portion between the anchor exterior surfaceand first and second laterally opposed portions of the socket wall.

In still yet another aspect, identical in form to the devices andinsertion systems previously herein described, the tensioning device hasa proximal handle portion that is an assembly of first and second rigidelements with an elastic element positioned therebetween. Applying adistal force to a first rigid element of the handle of the tensioningdevice causes deflection of the elastic element proportional to thetension in the graft attached to the distal fork. This allows thepractitioner to measure the tension in the graft. By establishing thetension in the graft to a predetermined value prior to placement of theanchor, the tension may then be maintained at the predetermined valueduring anchor placement.

These and other aspects are accomplished in the invention hereindescribed, directed to a system and method for producing a matrix ofimplants for the anchoring of a graft to bone. Further objects andfeatures of the invention will become more fully apparent when thefollowing detailed description is read in conjunction with theaccompanying figures and examples. For example, any graft fixationsystem that uses a non-rotating inner member (tensioning device) and amovable outer member (driver) to tension sutures in a prepared socketfor the placement of a simple one-piece cannulated anchor falls withinthe scope of this invention. However, it is to be understood that boththe foregoing summary of the invention and the following detaileddescription are of a preferred embodiment, and not restrictive of theinvention or other alternate embodiments of the invention. Inparticular, while the invention is described herein with reference to anumber of specific embodiments, it will be appreciated that thedescription is illustrative of the invention and is not constructed aslimiting of the invention.

BRIEF DESCRIPTION OF THE FIGURES

Various aspects and applications of the present invention will becomeapparent to the skilled artisan upon consideration of the briefdescription of figures and the detailed description of the presentinvention and its preferred embodiments that follows:

FIG. 1A is a plan view of the cannulated driver and anchor of an implantplacement system of the present invention.

FIG. 1B is an expanded view of the distal portion of the objects of FIG.1A at location C.

FIG. 1C is a side elevational sectional view of the objects of FIG. 1Aat location A-A of FIG. 1A.

FIG. 2A is a perspective view of the objects of FIG. 1A.

FIG. 2B is an expanded view of the distal portion of the objects of FIG.2A at location B.

FIG. 3 is a plan view of the tensioning device of an implant placementsystem of the present invention.

FIG. 4 is an expanded sectional view of the tensioning device of FIG. 3at location A-A.

FIG. 5 is an expanded view of the proximal hub portion of the tensioningdevice of FIG. 3 at location A.

FIG. 6 is a side elevational view of the objects of FIG. 3.

FIG. 7 is an expanded view of the objects of FIG. 6 at location B.

FIG. 8 is a perspective view of the tensioning device of FIG. 3.

FIG. 9 is an expanded view of the objects of FIG. 8 at location C.

FIG. 10 is a side elevational view of a key for an implant placementsystem of the present invention.

FIG. 11 is a perspective view of the objects of FIG. 10.

FIG. 12 is an exploded view of the assembly of a first embodiment of animplant placement system of the present invention.

FIG. 13 is a plan view of a fully assembled first embodiment of animplant placement system of the instant invention.

FIG. 14 is an expanded view of the distal portion of FIG. 13 at locationA.

FIG. 15 is an expanded side elevational sectional view of the objects ofFIG. 13 at location A-A.

FIG. 16 is a side elevational view of the objects of FIG. 13.

FIG. 17 is an expanded view of the objects of FIG. 13 at location B.

FIG. 18 is a perspective view of the objects of FIG. 13.

FIG. 19 is an expanded view of the objects of FIG. 13 at location C.

FIG. 20 is a perspective view of a first embodiment implant placementsystem with sutures being loaded into the system.

FIG. 21 is a perspective view of the first embodiment implant placementsystem with the sutures loaded.

FIG. 22 schematically depicts a socket placed in a bone prior to theplacement of an implant.

FIG. 23 depicts the first embodiment implant placement system positionedfor the first step of implant placement.

FIG. 24 depicts the proximal portion of the first embodiment implantplacement system during the first step of implant placement.

FIG. 25 depicts the distal portion of the first embodiment implantplacement system during the first step of implant placement.

FIG. 26 depicts the first embodiment implant placement system positionedfor the second step of implant placement.

FIG. 27 depicts the proximal portion of the embodiment implant placementsystem during the second step of implant placement.

FIG. 28 depicts the distal portion of the first embodiment implantplacement system during the second step of implant placement.

FIG. 29 depicts the first embodiment implant placement system positionedfor the third step of implant placement.

FIG. 30 depicts the proximal portion of the first embodiment implantplacement system during the second step of implant placement.

FIG. 31 depicts the distal portion of the first embodiment implantplacement system during the third step of implant placement.

FIG. 32 depicts the site at the completion of implant placement using animplant placement system of the instant invention.

FIG. 33 is a plan view of a second embodiment of an implant placementsystem of the instant invention wherein the tubular distal portion ofthe tensioning device is replaced by a rod having formed at its distalend a sharpened fork portion.

FIG. 34 is a side elevational view of the objects of FIG. 33.

FIG. 35 is an expanded proximal end view of the objects of FIG. 33.

FIG. 36 is an expanded plan view of the distal portion of the elementsof FIG. 33.

FIG. 37 is a side elevational view of the objects of FIG. 36.

FIG. 38 is a sectional view of the objects of FIG. 36 at location B-B.

FIG. 39 is a distal perspective view of the objects of FIG. 33.

FIG. 40 is an expanded view of the objects of FIG. 39 at location A.

FIG. 41 is a proximal perspective view of the objects of FIG. 33.

FIG. 42 is an expanded view of the objects of FIG. 41 at location B.

FIG. 43 depicts an alternate embodiment implant system of the presentinvention in use positioning sutures in a socket for the securing of agraft using an anchor.

FIG. 44 is an expanded view of the distal portion of the objects of FIG.43 depicting the placement site.

FIG. 45 depicts the alternate “fork” embodiment system with the suturestensioned so as to position the graft.

FIG. 46 is an expanded view of the distal portion of the objects of FIG.45 depicting the placement site.

FIG. 47 is an expanded view of the site depicting the system with theanchor placed.

FIG. 48 is an expanded view of the site at completion of the anchorplacement and removal of the system with the sutures trimmed.

FIG. 49 depicts a first step of an alternate repair method for securinga graft in a socket using an implant as contemplated by the presentinvention.

FIG. 50 depicts a second step of the alternate repair method

FIG. 51 depicts a third step of the alternate repair method.

FIG. 52 depicts the site of the graft attachment at the completion ofthe repair using the alternate repair method.

FIG. 53 depicts a first step of a second alternate repair method forsecuring a graft in a socket using an implant.

FIG. 54 depicts a second step of the alternate repair method

FIG. 55 depicts a third step of the alternate repair method.

FIG. 56 depicts a fourth step of the alternate repair method.

FIG. 57 depicts the site of the graft attachment at the completion ofthe repair using the alternate embodiment repair method.

FIG. 58 depicts a first step of a third alternate repair method forsecuring a graft in a socket using an implant.

FIG. 59 depicts a second step of the alternate repair method

FIG. 60 depicts a third step of the alternate repair method.

FIG. 61 depicts a fourth step of the alternate repair method.

FIG. 62 depicts a fifth step of the alternate repair method.

FIG. 63 depicts the site of the graft attachment at the completion ofthe repair using the alternate embodiment repair method.

FIG. 64 is a plan view of a distal assembly for the tensioning devicefor an alternate embodiment anchor placement system that includes aforce indicating inner tensioning assembly.

FIG. 65 is a side elevational view of the objects of FIG. 64.

FIG. 66 is a sectional view of the objects of FIG. 64 at location A-A.

FIG. 67 is an expanded proximal axial view of the objects of FIG. 64.

FIG. 68 is a perspective view of the objects of FIG. 64.

FIG. 69 is a expanded view of the proximal portion of the objects ofFIG. 68 at location A.

FIG. 70 is a plan view of the handle portion of a tensioning device foran alternate embodiment anchor placement system.

FIG. 71 is a side elevational view of the objects of FIG. 70.

FIG. 72 is a sectional view of the objects of FIG. 70 at location A-A.

FIG. 73 is a perspective view of the objects of FIG. 70.

FIG. 74 is an expanded proximal axial view of the objects of FIG. 70.

FIG. 75 is a perspective view of an end cap for the tensioning devicefor an alternate embodiment anchor placement system.

FIG. 76 is a plan view of the objects of FIG. 75.

FIG. 77 is a distal axial view of the objects of FIG. 75.

FIG. 78 is a side elevational view of the objects of FIG. 75.

FIG. 79 is a sectional view of the objects of FIG. 76 at location A-A.

FIG. 80 is a plan view of an alternate embodiment anchor placementsystem of the present invention that allows the surgeon to measure thetension in the graft during the attachment of the graft in accordancewith the methods of the present invention.

FIG. 81 is an expanded view of the proximal portion of the objects ofFIG. 80 at location A.

FIG. 82 is a perspective view of the objects of FIG. 80.

FIG. 83 is an expanded view of the proximal portion of the objects ofFIG. 82 at location A.

FIG. 84 is a central expanded side elevational sectional view of theobjects of FIG. 81.

FIG. 85 is a perspective view of a prior art system for knotless anchorfixation of a tissue graft.

FIG. 86 is a perspective view of a prior art system for knotless anchorfixation of a tissue graft.

FIG. 87 is a perspective view of the prior art system of FIG. 85positioning a graft for fixation prior to anchor placement.

FIG. 88 is a perspective view of the system of FIG. 87 with the anchorplaced.

FIG. 89 is a plan view of a prior art system for knotless anchorfixation of a tissue graft.

FIG. 90 is an expanded view of the objects of FIG. 89 at location A.

FIG. 91 is an expanded view of the distal portion of the objects of FIG.89 with suture loaded in preparation for use.

FIG. 92 is a proximal perspective view of an alternate embodiment anchorplacement system of the present invention.

FIG. 93 is an expanded view of the objects of FIG. 93 at location C.

FIG. 94A is an expanded distal perspective view of the distal portion ofthe objects of FIG. 92.

FIG. 94B is an expanded view of the objects of FIG. 94A at location D.

FIG. 95 is an expanded proximal perspective view depicting the alternateembodiment anchor placement system of FIG. 92 in use with a tendonsecured to the distal end of the tensioning device in preparation forplacement in a socket.

FIG. 96 is a distal perspective view of the objects of FIG. 95.

FIG. 97 is an expanded proximal perspective view of the distal portionof an alternate embodiment anchor system of the present invention.

FIG. 98 is a distal perspective view of the objects of FIG. 97.

FIG. 99 is a proximal perspective view of an anchor for an implantplacement system of the present invention.

FIG. 100 is a distal perspective view of the objects of FIG. 99.

FIG. 101 is a plan view of the objects of FIG. 99.

FIG. 102 is a sectional view of the objects of FIG. 101 at location A-A.

FIG. 103 is a proximal perspective view of an alternate embodimentanchor for an implant placement system of the present invention.

FIG. 104 is a distal perspective view of the objects of FIG. 103.

FIG. 105 is a plan view of the objects of FIG. 103.

FIG. 106 is a sectional view of the objects of FIG. 105 at location A-A.

FIG. 107 is a perspective view of the proximal handle portion of analternate embodiment of the present invention with the tensioning devicewithdrawn proximally a distance from the driver.

FIG. 108 is a plan view of the objects of FIG. 106.

FIG. 109 is a perspective view of the proximal handle portion of anotheralternate embodiment of the present invention with the tensioning devicewithdrawn proximally a distance from the driver.

FIG. 110 is a plan view of the objects of FIG. 109.

FIG. 111 is a plan view of the objects of FIG. 109 with the tensioningdevice fully inserted into the driver in preparation for use.

FIG. 112 is a plan view of the handle portion of another alternateembodiment of the present invention.

FIG. 113 is a sectional view of the objects of FIG. 112 at location A-A.

FIG. 114 is an expanded view of the objects of FIG. 113 at location C.

FIG. 115 is a perspective view of the handle portions of anotheralternate embodiment of the present invention.

FIG. 116 is a plan view of the objects of FIG. 115.

FIG. 117 is a perspective view of the hub portion of a tensioning devicefor an alternate embodiment implant placement system of the presentinvention.

FIG. 118 is a perspective view of the proximal portion of the handle ofa driver for an alternate embodiment implant placement system of thepresent invention.

FIG. 119 is a plan view of a driver for an alternate embodiment anchorsystem of the present invention.

FIG. 120 is an expanded view of the objects of FIG. 119 at location A.

FIG. 121 is a perspective view of the objects of FIG. 119.

FIG. 122 is an expanded view of the objects of FIG. 121 at location C.

FIG. 123 is a plan view of an insertion device for an alternateembodiment anchor system of the present invention.

FIG. 124 is a side elevational view of the objects of FIG. 123.

FIG. 125 is a perspective view of the objects of FIG. 123.

FIG. 126 is an expanded view of the objects of FIG. 125 at location A.

FIG. 127 is an expanded proximal perspective view of the proximalportion of the objects of FIG. 123.

FIG. 128 is an expanded plan view of the proximal portion of the objectsof FIG. 123.

FIG. 129 is a proximal axial view of the objects of FIG. 123.

FIG. 130 is an expanded distal perspective view of the proximal portionof the objects of FIG. 123.

FIG. 131 is a perspective view of an exploded assembly of an alternateembodiment implant placement system.

FIG. 132 is a perspective view of an assembled alternate embodimentimplant placement system.

FIG. 133A is an expanded distal perspective view of the objects of FIG.132 at location A.

FIG. 133B is an expanded proximal perspective view of the objects ofFIG. 133.

FIG. 134A is a side elevational view of the objects of FIG. 133A.

FIG. 134B is an expanded sectional view of the objects of FIG. 134A atlocation A-A.

FIG. 135 is an expanded proximal perspective view of the proximalportion of the objects of FIG. 132.

FIG. 136 is an expanded distal perspective view of the proximal portionof the objects of FIG. 132.

FIG. 137 is a perspective view of the alternate embodiment implantplacement system of FIG. 132 with suture loaded in preparation foraffixing tissue to a boney surface.

FIG. 138 is an expanded perspective view of the distal portion of theobjects of FIG. 137.

FIG. 139 is a plan view of an alternate embodiment implant of thepresent invention wherein torque is transmitted to the implant by aproximal laterally extending slot.

FIG. 140 is a side elevational view of the implant of FIG. 139.

FIG. 141 is a perspective view of the implant of FIG. 139.

FIG. 142 is a proximal axial view of the implant of FIG. 139.

FIG. 143 is an expanded sectional view of the implant of FIG. 139 atlocation A-A.

FIG. 144 is a plan view of the distal portion of an alternate embodimentimplant placement system of the present invention with which the implantof FIG. 139 may be placed.

FIG. 145 is a side elevational view of the objects of FIG. 144.

FIG. 146 is a perspective view of the objects of FIG. 144.

FIG. 147 is a side elevational view of the distal portion of the implantplacement system of FIG. 144 with the implant of FIG. 139 positionedthereon in preparation for use.

FIG. 148 is an expanded sectional view of the objects of FIG. 147 atlocation A-A.

FIG. 149 is a side elevational view of the distal portion of the implantplacement system and implant of FIG. 147 with a suture loaded to thesystem in preparation for use.

FIG. 150 is a perspective view of the objects of FIG. 149.

FIG. 151 is a perspective view of an alternate embodiment implant of thepresent invention.

FIG. 152 is a side elevational view of the implant of FIG. 151.

FIG. 153 is a proximal axial view of the implant of FIG. 151.

FIG. 154 is a perspective view of an alternate embodiment implant of thepresent invention.

FIG. 155 is a side elevational view of the implant of FIG. 154.

FIG. 156 is a sectional view of the implant of FIG. 155 at location A-A.

FIG. 157 is a side elevational view of an alternate embodiment implantof the present invention.

FIG. 158 is a proximal axial view of the implant of FIG. 157.

FIG. 159 is a sectional view of the implant of FIG. 157 at location A-A.

FIG. 160 is a perspective view of the implant of FIG. 157.

FIG. 161 is a perspective view of an alternate embodiment implant of thepresent invention forming an interference plug.

FIG. 162 is a plan view of the implant of FIG. 161.

FIG. 163 is a sectional view of the objects of FIG. 162 at location A-A.

FIG. 164 is a side elevational view of a the distal portion of analternate embodiment implant placement system configured for placing theinterference plug implant of FIG. 161.

FIG. 165 is a perspective view of the implant placement system of FIG.164.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Aspects of the present invention relate to and/or overlap with aspectsdescribed in related co-pending and contemporaneously filed applicationSer. No. 15/256,838 entitled “Implant Placement Systems And One-HandedMethods For Tissue Fixation Using Same” and Ser. No. 15/256,945“Multiple Implant Constructions And Fixation Methods AssociatedTherewith”, the entire contents of which are hereby incorporated intheir entirety.

Although any methods and materials similar or equivalent to thosedescribed herein can be used in the practice or testing of embodimentsof the present invention, the preferred methods, devices, and materialsare now described. However, before the present materials and methods aredescribed, it is to be understood that the present invention is notlimited to the particular sizes, shapes, dimensions, materials,methodologies, protocols, etc. described herein, as these may vary inaccordance with routine experimentation and optimization. It is also tobe understood that the terminology used in the description is for thepurpose of describing the particular versions or embodiments only, andis not intended to limit the scope of the present invention which willbe limited only by the appended claims. Accordingly, unless otherwisedefined, all technical and scientific terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich the present invention belongs. However, in case of conflict, thepresent specification, including definitions below, will control.

In the context of the present invention, the following definitionsapply:

The words “a”, “an” and “the” as used herein mean “at least one” unlessotherwise specifically indicated. Thus, for example, reference to an“opening” is a reference to one or more openings and equivalents thereofknown to those skilled in the art, and so forth.

The term “proximal” as used herein refers to that end or portion whichis situated closest to the user of the device, farthest away from thetarget surgical site. In the context of the present invention, theproximal end of the implant system of the present invention includes thedriver and handle portions.

The term “distal” as used herein refers to that end or portion situatedfarthest away from the user of the device, closest to the targetsurgical site. In the context of the present invention, the distal endof the implant systems of the present invention includes componentsadapted to fit within the pre-formed implant-receiving socket.

In the context of the present invention, the terms “cannula” and“cannulated” are used to generically refer to the family of rigid orflexible, typically elongate lumened surgical instruments thatfacilitate access across tissue to an internally located surgery site.

The terms “tube” and “tubular” are interchangeably used herein to referto a generally round, long, hollow component having at least one centralopening often referred to as a “lumen”.

The terms “lengthwise” and “axial” as used interchangeably herein torefer to the direction relating to or parallel with the longitudinalaxis of a device. The term “transverse” as used herein refers to thedirection lying or extending across or perpendicular to the longitudinalaxis of a device.

The term “lateral” pertains to the side and, as used herein, refers tomotion, movement, or materials that are situated at, proceeding from, ordirected to a side of a device.

The term “medial” pertains to the middle, and as used herein, refers tomotion, movement or materials that are situated in the middle, inparticular situated near the median plane or the midline of the deviceor subset component thereof.

As discussed above, when a tissue, more particularly a soft connectivetissue in a joint space, becomes damaged or torn from its associatedbone or cartilage, surgery is usually required to reattach the tissue orreconstruct the bone. The present invention is directed to various meansand mechanisms for securing the displaced tissue to boney tissue.

As used herein, the term “tissue” refers to biological tissues,generally defined as a collection of interconnected cells that perform asimilar function within an organism. Four basic types of tissue arefound in the bodies of all animals, including the human body and lowermulticellular organisms such as insects, including epithelium,connective tissue, muscle tissue, and nervous tissue. These tissues makeup all the organs, structures and other body contents. While the presentinvention is not restricted to any particular soft tissue, aspects ofthe present invention find particular utility in the repair ofconnective tissues such as ligaments or tendons, particularly those ofthe shoulder, elbow, knee or ankle joint.

In a similar fashion, while the present invention is not restricted toany particular boney tissue, a term used herein to refer to both bonesand cartilage, aspects of the present invention find particular utilityin the repair or reattachment of connective tissues to the boneyelements of the shoulder, elbow, knee or ankle joint.

When the damaged tissue is of sufficient quantity and quality, thedamaged portion may simply be directly reattached to the bone from whichit was torn so that healing back to the bone can take place. However, inother situations, a “graft” may be needed to stimulate regrowth andpermanent attachment. In the context of the present invention, the term“graft” refers to any biological or artificial tissue being attached tothe boney tissue of interest, including:

-   -   Autografts, i.e., grafts taken from one part of the body of an        individual and transplanted onto another site in the same        individual, e.g., ligament graft;    -   Isografts, i.e., grafts taken from one individual and placed on        another individual of the same genetic constitution, e.g.,        grafts between identical twins;    -   Allografts, i.e., grafts taken from one individual placed on        genetically non-identical member of the same species; and    -   Xenografts, i.e., grafts taken from one individual placed on an        individual belonging to another species, e.g., animal to man.        Autografts and isografts are usually not considered as foreign        and, therefore, do not elicit rejection. Allografts and        xenografts are recognized as foreign by the recipient thus carry        a high risk of rejection. For this reason, autographs and        isografts are most preferred in the context of the present        invention.

Surgical interventions such as contemplated herein generally require theboney tissue to be prepared for receiving the graft. In the context ofthe present invention, such preparation includes the formation of a“socket”, i.e., a hole punched or drilled into the bone into which aprosthetic device such as an implant may be received. The socket may beprepared at the desired target location using conventional instrumentssuch as drills, taps, punches or equivalent hole-producing devices.

While certain procedures contemplate directly attaching the graft to thebone, the more common route involves the employment of an implantspecially configured to hold and/or enable attachment of the graft tothe boney tissue. As used herein, the term “implant” refers to aprosthetic device fabricated from a biocompatible and/or inert material.In the context of the present invention, examples of such “implants”include conventional and knotless anchors of both the screw-threaded andinterference-fit variety.

In certain embodiments, the present invention contemplates fabricationof the implant from either a metallic material or a suitable polymericmaterial, including, but not limited to, polyetheretherketone (PEEK), apolymeric composite such as, for instance, carbon fiber reinforced PEEK(PEEK CF), or of a suitable bioabsorbable material such as, forinstance, polylactic acid (PLA). Equivalent materials are alsocontemplated for use herein.

The preferred implant system of the present invention is comprised of anoptionally cannulated tensioning device (also referred to as the“inserter” or “insertion device”) slidably received within the lumen ofa cannulated driver device (also referred to as the implant driver) thattogether serve to tension sutures in a prepared socket for the placementof a simple one-piece cannulated anchor. In the Examples below, thepresent invention makes reference to various lock-and-key type matingmechanisms that serve to establish and secure the axial and rotationalarrangement of these device components. It will again be readilyunderstood by the skilled artisan that the position of the respectivecoordinating elements (e.g., recessed slots and grooves that mate withassorted projecting protrusions, protuberances, tabs and splines) may beexchanged and/or reversed as needed.

The implant placement system of the present invention requires a robustconnection between the “driver device” and the associated “implant” or“anchor” so as to ensure that the two rotate as a single unit such thatrotational force or “torque” applied to the proximal end of the system(e.g., via the proximal handle portion of the driver device) istransmitted to the distal end of the system (e.g., the distal end of theimplant disposed in the prepared socket) without incident orinterruption. This continuous “torque transfer” along the length of thesystem, from proximal to distal end, is critical to the function of thedriver, enabling it to distally advance the implant and firmly securethe implant (and any associated sutures or tissues) in the biologicalsite of interest. In the context of the present invention, thiscontinuous torque transfer is achieved by means of coordinating“torque-transmitting” elements, namely a distal “torque-transmittingportion” of the driver device that is configured to mate with and/orconform to a “torque-transmitting” (or alternatively “torque-receiving”or “torque-transferring”) portion of the implant, such “portion”including at a minimum the proximal end of the implant though thepresent invention contemplates embodiments where “torque-transmitting”features on the implant extend along the length of the implant. Therespective “torque-transmitting” features on the driver device andimplant cooperate to ensure that any proximal torque applied by the userto the proximal handle portion of the device is directly conveyed(“transmitted”) to the distal end of the implant.

The present invention makes reference to insertion devices commonlyreferred to in the art as “drills” and “drivers”, i.e., devices that“drill” the socket and “drive” the implant into the socket. In thecontext of the present invention, the drills and drivers may beconventional, e.g., rigidly linear as previously herein described, or,as discussed in detail herein, “off-axis”, e.g., having an angularlyoffset distal portion adapted to drill off-axis sockets in boney tissuesthat are remote and difficult to access and drive therein thecorresponding implant, such as an anchor or interference screw.

The present invention contemplates securing the graft to the implant viasutures. In the context of the present invention, the term “suture”refers to a thread-like strand or fiber used to hold body tissues aftersurgery. Sutures of different shapes, sizes, and thread materials areknown in the art and the present invention is not restricted to anyparticular suture type. Accordingly, in the context of the presentinvention, the suture may be natural or synthetic, monofilament ormultifilament, braided or woven, permanent or resorbable, withoutdeparting from the spirit of the invention.

In certain embodiments, the present invention makes reference to anelongate element of a superelastic and/or shape memory materialconfigured to include a suture retention loop at its distal end anddesigned to be slidably received within a lumen of a cannulatedtensioning device or inserter. In certain preferred examples, theelongate element takes the form of a “nitinol wire”. In the context ofthe present invention, “nitinol” is a super elastic metal alloy ofnickel and titanium. In a preferred embodiment, the two elements arepresent in roughly equal atomic percentage (e.g., Nitinol 55, Nitinol60). Nitinol alloys exhibit two closely related and unique properties:shape memory effect (SME) and superelasticity (SE; also calledpseudoelasticity, PE). Shape memory is the ability of nitinol to undergodeformation at one temperature then recover its original, undeformedshape upon heating above its “transformation temperature”.Superelasticity occurs at a narrow temperature range just above itstransformation temperature; in this case, no heating is necessary tocause the undeformed shape to recover, and the material exhibitsenormous elasticity, some 10-30 times that of ordinary metal.

The present invention also makes reference to high strength polymericmaterials and high tensile strength ceramic materials such as alumina orzirconia that may be formed to complex shapes by a process referred toas Ceramic Injection Molding (CIM). In this process, ceramic powder anda binder material are molded to a shape that is subsequently fired in afurnace to eliminate the binder material and sinter the ceramic powder.During this sintering operation the item is reduced in size by twenty tothirty percent and achieves near 100% density with very high dimensionalrepeatability. Ceramic materials that are routinely molded and thuscontemplated by the present invention include, but are not limited to,alumina, zirconia toughened alumina (ZTA) and partially stabilizedzirconia (PSZ). The flexular strengths of these materials range from55,000 psi to 250,000 psi, far higher than the 25,000 psi flexularstrength of implantable PEEK material.

The instant invention has both human medical and veterinaryapplications. Accordingly, the terms “subject” and “patient” are usedinterchangeably herein to refer to the person or animal being treated orexamined. Exemplary animals include house pets, farm animals, and zooanimals. In a preferred embodiment, the subject is a mammal, morepreferably a human.

Hereinafter, the present invention is described in more detail byreference to the Figures and Examples. However, the following materials,methods, figures, and examples only illustrate aspects of the inventionand are in no way intended to limit the scope of the present invention.For example, while the present invention makes specific reference toarthroscopic procedures, it is readily apparent that the teachings ofthe present invention may be applied to other minimally invasiveprocedures and are not limited to arthroscopic uses alone. As such,methods and materials similar or equivalent to those described hereincan be used in the practice or testing of the present invention.

EXAMPLES

FIGS. 85 through 88 depict a prior art device and method for theplacement of a knotless suture anchor. Cannulated driver 100 has ahandle portion 102 and a distal hexagonal portion 104 that protrudesbeyond anchor 106. Suture 108 in the cannulation of driver 100 forms aloop at the distal end of distal hexagonal portion 104. In FIG. 85,sutures 110, which have been passed through graft 112, are positionedwithin the distal loop of sutures 108 where they are secured against thedistal end of distal hexagonal portion 104 by tension applied by thesurgeon to the proximal ends of sutures 108. Alternatively, graft 112may be positioned within the distal loop of suture 108 and securedagainst the distal end of distal hexagonal portion 104 and maintained inthat position by tension applied to sutures 108. Substantial tensionmust be maintained in sutures 108 when graft 112 is secured in thismanner to ensure that the position of graft 112 does not change duringinsertion of the graft into the prepared socket and placement of anchor106. In FIG. 86, sutures 110 have been drawn into the lumen of hexagonaldistal portion 104 of driver 100. Subsequently, sutures 110 are placedunder tension by the surgeon so as to secure graft 112 to the distal endof distal hexagonal portion 104 of driver 100. In FIG. 87, distalhexagonal portion 104 of driver 100, along with the sutures/graftsecured to its distal end, have been inserted into a prepared socketthereby drawing graft 112 to the desired position. In FIG. 88, implant106 has been screwed into the prepared socket thereby securing graft112. Because sutures 110 or graft 112 are/is secured or captured at thedistal end of rotating driver 100 by tensioned sutures 108 or 110,friction between the sutures 110 and the distal end of the driver 100 orbetween graft 112 and the distal end of driver 100 transmits torque tothe sutures or graft. This transmitted torque may cause suture spin,graft shift, or improper tensioning of the construct.

FIGS. 89 through 91 depict another prior art device 200. Cannulateddriver 200 has a handle portion 202 and a distal hexagonal portion 204that protrudes beyond anchor 206. Suture 208 in the cannulation ofdriver 200 is looped through aperture 231 of implant 230. Tensionapplied to the proximal ends of suture 208 retains implant 230 in thedistal end of hexagonal portion 204. As depicted in FIG. 91, during useone or more sutures 210 are threaded through eyelet 232 of implant 230.During use the distal portion of hexagonal portion 204 with implant 230mounted to its distal end is inserted into a prepared socket and sutures210 are tensioned to move the graft to its intended position.Thereafter, anchor 206 is screwed into the socket; suture 208 isreleased thereby freeing implant 230 from driver 200; and driver 200 isremoved, following which the sutures are trimmed proximal to anchor 206.Although implant 230 is pivotably mounted to the distal end of hexagonaldrive portion 204, due to friction between implant 230 and the distalend of hexagonal drive portion 204 in which it is retained by tension insuture 208, some level of torque is transmitted to implant 230, andtherethrough to suture(s) 210. This torque transmitted to implant 230may cause twisting of suture(s) 210 leading to improper tensioning andgraft shift, a negative effect referred to in the art as “suture spin”.

The present invention attempts to address these afore-noted problems inthe art. To that end, FIGS. 1A through 1C and 2A and 2B depict acannulated driver 1500 for a knotless anchor system of the instantinvention. Driver 1500 has a proximal handle 1502 in which is formed aproximal cylindrical recess 1504, and off-axis lateral holes 1506, and atubular distal portion 1510 having at its distal end drive element 1512.The distal portion 1514 of drive element 1512 is configured to becomplementary to internal drive features 1602 in the proximal portion ofthe lumen of cannulated threaded anchor 1600; accordingly, torquesupplied by driver 1500 is transmitted to anchor 1600 thereby. Thedistal torque-transmitting portion 1514 of drive element 1512 may befabricated in a variety of sizes, shapes, configurations and lumen sizesto suit a variety of anchors 1600, the requirements for a particularanchor 1600 depending on its size, configuration and materialproperties. For example, the complementary drive elements may take theform of an internally or externally positioned hexagonal or squaredrive, an internal or external spline, or slots positioned internal orexternal to the anchor. However, the present invention contemplatesalternate cooperating configurations and thus is not limited to any oneparticular embodiment.

Referring now to FIGS. 3 through 9, cannulated tensioning device 1400has a proximal hub 1402 optionally provided with a distal cylindricalportion 1404 in which are formed off-axis lateral grooves 1406, andcleats 1408 formed in the proximal rim of proximal hub 1402. Tensioningdevice 1400 has a tubular middle portion 1410, and a tubular distalportion 1412, distal portion 1412 having a diameter 1414 and length1416. Diameter 1414 is selected such that distal portion 1412 may beslidably positioned within distal drive element 1512 of cannulateddriver 1500. Length 1416 is determined such that when tensioning device1400 is positioned within the lumen of the cannulated driver 1500,distal portion 1412 of tensioning device 1400 protrudes beyond distaldrive element 1512 of driver 1500 a sufficient distance so that whenanchor 1600 is mounted on distal drive element 1512 and distal portion1412 is inserted to the full depth of a suitable socket formed in bone,anchor 1600 is still proximal to and clear of the socket. Elongate wireelement 1302 having at its distal end loop 1304 and at its proximal endpolymeric element 1306 forming a pull-tab forms a loading loop 1300 fordrawing sutures into the lumens of tubular members 1410 and 1412.

Implant 1600 may be formed of a metallic material, a suitable polymericmaterial such as, for instance, polyetheretherketone (PEEK), a polymericcomposite such as, for instance, carbon fiber reinforced PEEK (PEEK CF),or of a suitable bioabsorbable material such as, for instance,polylactic acid (PLA). FIGS. 10 and 11 depict an illustrative embodimentof removable key 1200 that may serve to prevent relative axial androtational movement between the cannulated driver and the tensioningdevice. In this embodiment, key 1200 has a planar portion 1202 andcylindrical portions 1204 that are sized and spaced such thatcylindrical portions 1204 may be inserted into off-axis lateral holes1506 of handle 1502 of cannulated driver 1500.

FIG. 12 depicts cannulated driver 1500 with anchor 1600 loaded thereto,tensioning device 1400 with loading loop 1300 positioned for loading asuture, and key 1200 prior to mounting of driver 1500 to tensioningdevice 1400 in preparation for use. When driver 1500 is mounted totensioning device 1400, off-axis slots 1406 of handle 1402 of tensioningdevice 1400 are aligned with off-axis holes 1506 of handle 1502 ofdriver 1500 and cylindrical portions 1204 of key 1200 are inserted intothe passages so formed. Positioning of key 1200 in this manner preventsaxial and rotational movement of tensioning device 1400 relative todriver 1500. FIGS. 13 through 19 depict knotless suture anchor system1000 of the instant invention prepared for use with key 1200 and loadingloop 1300 in place.

Sutures 1800 are loaded into system 1000 by placing the proximal ends ofsutures 1800 in distal loop 1304 of loading loop 1300 as depicted inFIG. 20. Tab 1306 of loading loop 1300 is withdrawn proximally untilproximal ends 1802 of sutures 1800 extend proximally beyond hub 1402 oftensioning device 1400 as depicted in FIG. 21.

The present invention may be used to secure any type of soft tissue,graft, or tendon, such as, for example, a biceps tendon or a rotatorcuff. An illustrative method of fixation according to the principles ofthe instant invention is depicted in FIGS. 22 through 32. FIG. 22Aschematically depicts a socket 32 formed by drilling or punching in bone30, and a graft 20 to be affixed to bone 30. Sutures 1800 are passedthrough graft 20 in a usual manner; and the sutures loaded into system1000 as previously described and depicted in FIGS. 20 and 21, such thatsuture proximal ends 1802 are accessible to the surgeon. Subsequently,distal tubular portion 1412 of tensioning device 1400 is inserted intosocket 32 as depicted in FIGS. 23 through 25, the distal end of tubularportion 1412 contacting the bottom surface of socket 32. Thereafter,referring to FIGS. 26 through 28, the surgeon grasps proximal ends 1802of sutures 1800 and withdraws them proximally so as to advance graft 20towards socket 32. When graft 20 is in the desired position, proximalends 1802 of sutures 1800 are secured in cleats 1408 to maintain thegraft position. So long as proximal ends 1802 of sutures 1800 remainsecurely cleated and the distal end of tubular element 1412 ismaintained in contact with the bottom surface of socket 32, the positionof graft 20 will not change. The surgeon may adjust sutures 1800 asrequired to achieve optimal placement of graft 20. When this optimalplacement of graft 20 has been achieved, while maintaining contactbetween the distal end off distal tubular element 1412 and the bottom ofsocket 32, the surgeon removes key 1200 from system 1000 so as to allowaxial and rotational movement of driver 1500. The surgeon then advancesanchor 1600 to socket 32 and screws the anchor into socket 32 so as totrap sutures 1800 between anchor 1600 and the wall of socket 32 in bone30 as depicted in FIGS. 29 through 31. When anchor 1600 is fullyinserted in socket 32, proximal ends 1802 of sutures 1800 are releasedfrom cleats 1408 and system 1000 is withdrawn from the joint, leavingthe repair site as depicted in FIG. 32. Subsequently sutures 1800 arecut adjacent to anchor 1600 and the anchor placement is complete.

In an alternate method for anchor placement according to the presentinvention, the process may be simplified through use of an alternateembodiment system of the present invention in which the sutures are notdrawn into a cannulation of the tensioning device, but rather arepositioned and retained within a forked portion formed at the distal endof the tensioning device. In this alternate embodiment, sutures do notenter the lumen of the cannulated anchor, but rather wrap around thedistal end of the anchor during insertion and are retained in place byfriction between the external surfaces of the anchor and the boneysurface of the socket at laterally opposed locations.

Alternate embodiment anchor placement system 2000, depicted in FIGS. 33through 42, is identical to system 1000 in all aspects except asspecifically subsequently described. Specifically, cannulated distaltubular element 1412 of system 1000 is replaced by distal element 2442that is not cannulated and has formed at its distal end elongatelaterally opposed, distally extending portions 2444 with sharpeneddistal ends 2448. Elongate portions 2444 form the tines of a fork withchannel 2446 formed between portions 2444. Tensioning device handle 2402has formed near the distal end of its external surface flanges 2430wherein are formed slots 2432 which serve as cleats for maintaining thetension of sutures placed therein, flanges 2430 and slots 2432 replacingslots 1408 in hub 1402 of system 1000.

A method of fixation according to the principles of the instantinvention using system 2000 is depicted in FIGS. 43 through 48. A socket2032 is formed by drilling or punching a suitable “hole” in bone 2030.Sutures 2800 are passed through graft 2020 in a usual manner. Sutures2800 are positioned within channel 2446 at the distal end of distalelement 2442 of the tensioning device and distal element 2442 isinserted into socket 2032 such that the distal end of elongate portions2444 contact the bottom of the socket as depicted in FIGS. 43 and 44.Thereafter, referring to FIGS. 45 and 46, the surgeon grasps proximalends 2802 of sutures 2800 and withdraws them proximally so as to advancegraft 2020 towards socket 2032. When graft 2020 is in the desiredposition, proximal ends 2802 of sutures 2800 are secured in cleats 2432in flanges 2430 of handle 2402 to maintain the graft position. So longas proximal portions 2802 of sutures 2800 remain cleated and the distalend of distal tensioning element 2442 is maintained in contact with thebottom surface of socket 2032, the position of graft 2020 will notchange. The surgeon may adjust sutures 2800 as required to achieveoptimal placement of graft 2020. When this optimal placement of graft2020 has been achieved, while maintaining contact between the distal endoff distal tubular element 2442 and the bottom of socket 2032, thesurgeon removes key 2200 from system 2000 so as to allow axial androtational movement of the driver assembly. The surgeon advances anchor2600 to socket 2032 and screws the anchor into socket 2032 so as to trapsutures 2800 between anchor 2600 and the walls of socket 2032 in bone2030 as depicted in FIG. 47. When anchor 2600 is fully inserted insocket 2032, proximal portions 2802 of sutures 2800 are released fromcleats 2432 and system 2000 is withdrawn from the joint. Subsequentlysuture proximal portions 2802 of sutures 2800 are cut adjacent to anchor2600 and the anchor placement is complete. The position of the graft ismaintained by friction between the sutures 2800 that are trapped betweenthe exterior surface of anchor 2600 and two laterally opposed portionsof the walls of socket 2032.

Anchor placement systems of the present invention are also useful forthe attachment of tendons in a procedure called bio-tenodesis. Whenattaching, for instance, a biceps tendon to the humeral shaft, theproximal end of the tendon is inserted into the socket and the implantplaced in a manner that traps the tendon between the anchor and the wallof the socket thereby retaining the tendon in the socket.

FIGS. 49 through 52 depict an alternate embodiment method for fixationof a tendon graft using system 2000. As is commonly done in preparationfor bio-tenodesis, the portion of the graft that is to be inserted intothe socket is first sutured in a circumferential manner, the suturesproviding added resistance to pull-out when the repair is completed.Excess suture from the circumferential suturing (also called “whipstitching”) is used to position the tendon prior to anchoring by theimplant. Unlike previous embodiment methods disclosed herein, thepositioning of graft 3020 is not achieved by tensioning the suturesafter distal element 3442 is inserted into socket 3032. Rather, asdepicted in FIG. 49 sutures 3802 are positioned within channel 3446 atthe distal end of distal element 3442 of the tensioning device andtensioned such that graft 3020 is positioned and retained adjacent tothe distal end of distal element 3442 adjacent to distally extendingportions 3444. Tension in sutures 3802 is then maintained by cleating inthe manner previously herein described. Thereafter, distal element 3444is inserted into socket 3032 as shown in FIG. 50 and anchor 3600 isplaced as depicted in FIG. 51 trapping graft 3020 between anchor 3600and the boney surface of the wall of socket 3032 at a first location,and trapping sutures 3082 between anchor 3600 and the boney surface ofthe wall of socket 3032 at a second location. Friction forces acting atthese locations maintain the position of graft 3020 relative to socket3032 and bone 3030. FIG. 52 depicts the site at completion of the anchorplacement and removal of insertion system 3000.

FIGS. 53 through 57 depict an alternate embodiment method of anchoring agraft to bone using the alternate anchor placement system 2000 of thepresent invention. Rather than using tensioned sutures to maintain theplacement of a graft at the distal end of distal element 3442 aspreviously depicted in FIG. 49, the graft is impaled on the distallyextending portions 3444 of distal element 3442 as shown in FIGS. 53 and54, the sharpened distal ends 3448 of extending portions 3444penetrating the graft. Thereafter, distal element 3444 is inserted intosocket 3032 as shown in FIG. 55 and anchor 3600 is placed as depicted inFIG. 56 trapping graft 3020 between anchor 3600 and the boney surface ofthe wall of socket 3032. Friction force between the inserted portion ofgraft 3020 and socket 3032 maintains the position of graft 3020 relativeto socket 3032 and bone 3030. FIG. 57 depicts the site at completion ofthe anchor placement and removal of insertion system 3000. If the grafthas been whip-stitched and the excess suture remains, the suture tailswill also be trapped between anchor 3600 and socket 3032 therebyproviding additional resistance to pull out.

FIGS. 58 through 63 depict yet another alternate method for securing aligament graft to bone using anchor system 2000. As in the previousembodiments, sutures are not used to position and tension the graft 3020in socket 3032. Rather, as in the previous method, graft 3020 is impaledon the distally extending portions 3444 of distal element 3442 as shownin FIGS. 58 and 59, the sharpened distal ends to of extending portions3444 penetrating the graft. The site for penetration is selected suchthat when the ligament is inserted to the bottom of socket 3032 theproximal end of graft 3020 protrudes above the rim of socket 3032. Asseen in FIG. 60, graft 3020 is positioned above socket 3032, inserted asshown in FIG. 61, and anchor 3600 placed as shown in FIG. 62. FIG. 63shows the completed repair. Graft 3020 is trapped between the exteriorsurface of anchor 3600 and first and second laterally opposed portionsof the wall of socket 3032 and retained in position by frictiontherefrom.

It may be useful to determine the tension in a tendon undergoing atenodesis procedure so that optimal tension may be selected based on theparticular anatomy. In another embodiment of the instant invention, theinner tensioning member is provided with a mechanism that indicates theforce being applied to the graft during insertion into the socket. Theinsertion site on the graft may be adjusted such that when the graft isinserted to the bottom of the socket the predetermined optimal tensionis achieved, and thereafter maintained during anchor placement.

FIGS. 64 through 69 depict a distal assembly 4401 for a force indicatingmechanism for use with an inner tensioning assembly in accordance withthe present invention. Elongate tubular element 4410 has at its distalend distal element 4442, identical to distal element 3442 (FIGS. 36through 40), and at its proximal end element 4450 affixed thereto.Element 4450 has a cylindrical outer surface portion 4452 and a planarouter surface portion 4454. The proximal end of tubular element 4410 isthen positioned within lumen 4456. Recess 4458 extends distally fromproximal-most surface 4451.

FIGS. 70 to 74 depict a handle 4402 for a force indicating innertensioning assembly. Handle 4402 is identical to handle 2402 in allaspects except as subsequently described. Specifically, handle 4402 hasa distal lumen 4491 with a diameter that allows tubular element 4410 tobe slidably positioned therein. Recess 4496 extends distally fromproximal-most surface 4403 of handle 4402 and has a cylindrical surfaceportion 4497 and a planar portion 4498 sized such that element 4450 maybe positioned therein. This construction is such that when distalassembly 4401 is assembled to handle 4402 with element 4450 positionedwithin recess 4496 and tubular member 4410 is positioned within lumen4491 of handle 4402, distal assembly 4401 may be move axially relativeto handle 4402 but rotation is prevented. Handle 4402 has a window 4490formed in its top surface with adjacent beveled surfaces 4492 so thatrecess 4496 and elements therein may be viewed.

FIGS. 75 through 79 depict a proximal end cap 4700 for handle 4402. Endcap 4700 has a distal portion 4702 with proximally extending recess4704, and a proximal portion 4706. Distal portion 4702 is configured forassembly to handle 4402.

Referring now to FIGS. 80 through 84 which depict a force indicatinganchor system 4000 of the instant invention, distal assembly 4401 may beassembled to handle 4402 as previously described, and end cap 4700 isassembled to the proximal end of handle 4402. Spring 4900 is positionedtherebetween with its distal end in recess 4458 of element 4450 and itsproximal end in recess 4704 of end cap 4700. As seen in FIG. 81, indicia4470 are formed on beveled surfaces 4492 such that the position ofproximal-most surface 4451 of element 4450 visible through window 4490may be quantified. The position of element 4450 and its proximal-mostsurface 4451 is determined by the amount of deflection of spring 4900,which is in turn determined by the force exerted on distal assembly4401. This force is exerted on distal assembly 4401 by tension in thegraft during insertion into a socket by distal element 4442. Device 4000may be calibrated so that during insertion of the graft into the socketby the surgeon, by observing the position of proximal-most surface 4451relative to the indicia, will know the insertion force and thereby thetension in the graft.

When performing a bio-tenodesis type procedure such as depicted in FIGS.53 through 57 and in FIGS. 58 through 63, it may be possible for thegraft 3020 to become dislodged from distally extending portions 3444 oftensioning distal element 3442. This problem is addressed in analternate embodiment implant placement system 5000 of the presentinvention depicted in FIGS. 92 through 94. Therein, a suture loopreleasably maintains the position of the graft during manipulation andplacement. Placement system 5000 is alike in all aspects to system 2000except as specifically described hereafter. Specifically, distal element5442 of tensioning device 5400 is cannulated and handle 2402 oftensioning device 2400 is replaced by handle 5402 which is identical tohandle 1402 of tensioning device 1400 (FIGS. 3 through 9). Suture 5820has a distal portion forming a loop 5822 distal to the distal end ofdistal element 5442 of tensioning device 5400. Suture 5820 extendsproximally through the cannulation of distal element 5442 of tensioningdevice 5400, and proximally therefrom such that proximal portions 5824of suture 5820 extend beyond handle 5402. This allows the surgeon toapply tension to the suture loop 5822 so as to secure a graft placedtherein, and to maintain that tension by securing proximal portions 5824in slots 5408 of handle 5402. FIGS. 95 and 96 depict the distal portionof system 5000 as in use wherein a graft 5020 impaled on distal portions5444 of tensioning device 5400 as previously herein described andreferenced in FIGS. 53 through 63. As depicted in FIGS. 95 and 96,tension applied to proximal portions 5824 of suture 5820 has drawnsuture loop 5822 tightly around graft 5020 and secured graft 5020 to thedistal end of distal element 5442 in a manner that preventsdisengagement of graft 5020 from distally extending portions 5444 ofdistal element 5442. The placement of implant 5600 is accomplished inthe same manner as implant 3600 in FIGS. 53 through 63 and previouslyherein described except for the added steps of: (i) securing graft 5020to the distal end of distal element 5444 using suture 5820 as previouslydescribed; (ii) placing implant 5600 as depicted in FIGS. 56 and 62;(iii) releasing proximal ends 5824 of suture 5820 from slots 5408 ofhandle 5402; and (iv) at the completion of the anchor placement asdepicted in FIGS. 57 and 63, trimming the suture 5820 adjacent toimplant 5600 or withdrawing suture 5820 from the site.

Unlike prior art device 100, wherein suture loop 108 is adjacent to thedistal end of driver 104 which rotates during suture placement (see FIG.85), loop 5820 passes from the distal end of the non-rotating tensioningdevice 5400 and removably affixes graft 5020 thereto. Accordingly, notorque is transmitted to graft 5020 and twisting of graft 5020 is whollyprevented. Moreover, graft 5020 cannot easily slip from suture loop 5820since it is additionally impaled on distally extending portions 5444 ofdistal element 5442 of tensioning device 5400.

In other embodiments, distally extending portions 5444 of distal element5442 are eliminated. For instance, FIGS. 97 and 98 depict the distalportion of an anchor placement system 6000 in which the distal end 6443of distal element 6442 of a tensioning device 6400 has formed thereonserrations that penetrate the graft when suture loop 6822 is tightenedso as to prevent the graft from slipping out of loop 6422 duringinsertion of the graft into a socket. Distal end 6443 of distal element6442 of tensioning device 6400 may have other features formed thereon toaid in maintaining the graft position within suture loop 6822.Illustrative examples of such features include, but are not limited to,notches, slots, protuberances and/or recesses or projecting portions.Accordingly, the present invention is not limited to any one particularconfiguration.

Indeed, implant placement system 1000 (FIGS. 1 through 19) may be usedin the same manner as placement systems 5000 and 6000 if a suture loopis formed distal to the distal end of tubular distal element 1412 oftensioning device 1400. Because distal element 1412 does not rotateduring anchor placement, no torque is transmitted to the graft. Thisallows the graft to be affixed to the distal end of distal element 1412with sufficient resistance to removal of the graft from the suture loopso that the graft may be reliably inserted into a prepared socket foranchor placement.

FIGS. 99 through 102 depict anchor 3600 of anchor system 3000 depictedin FIGS. 46 through 63. Anchor 3600 of length 3608 has a threaded outersurface 3610, and a central lumen with a drive portion 3602 extendingdistance 3606 from the proximal end surface of anchor 3600. Distal tolumen drive portion 3602, cylindrical lumen portion 3604 extends to thedistal end of anchor 3600.

FIGS. 103 through 106 depict anchor 5600 of anchor system 5000 of FIGS.94A through 96, and of anchor system 6000 of FIGS. 97 and 98. Anchor5600 is identical to anchor 3600 in all respects except as specificallydescribed below. Specifically, lumen drive portion 5602 extends from theproximal end of anchor 5600 to the distal end of anchor 5600. Duringuse, as best seen in FIGS. 94A, 94B, 96 and 98, the distal drive portionof distal drive element 5512 extends the length of anchor 5600, thedistal-most surface of distal drive element 5512 being flush with, or ashort distance beyond the distal-most surface of anchor 5600.

The length 3606 of the drive portion 3602 of an anchor of the presentinvention is a matter of design choice and may be based on themechanical properties of the material from which anchor 3600 is made.For anchors 3600 formed of a low-strength material such as, forinstance, a bio-absorbable material, it may be desirable to have thetorque transmission portion 3602 of the central lumen extend for a largeportion of the length of the anchor, or, as in anchor 5600, extend theentire length of the anchor. Any cannulated threaded anchor may be usedwith anchor systems of the present invention.

Certain embodiments of the present invention previously described hereininclude an optional key to prevent angular and axial movement of thedriver relative to the tensioning device prior to anchor placement.Removal of the key allows the driver to advance the anchor to the socketand to place the anchor in the socket as previously herein described. Inother embodiments of the present invention, this key may be eliminatedand other alternative mechanisms may be used to prevent unintended axialand rotational motion of the driver relative to the tensioning device.

FIGS. 107 and 108 depict the proximal handle portion of system 6000.Device 6000 is identical to device 1000 (FIGS. 1 through 19) in allaspects of construction and use except as subsequently described herein.Specifically, in FIGS. 107 and 108, tensioning device 6400 is withdrawnproximally to reveal features of hub 6402 and handle 6502. Key 1200 ofdevice 1000 is eliminated along with cooperative mating features oftensioning device 1400 and driver 1500 that secure driver 1500 totensioning device 1400 when key 1200 is in place (see FIG. 12).Cylindrical distal portion 6404 of hub 6402 has formed therein a groovein which elastomeric o-ring 6002 is seated. When o-ring 6002 isassembled to distal portion 6404 of hub 6402 as depicted, the outerdiameter of o-ring 6002 is slightly larger than the diameter of proximalcylindrical recess 6504 of handle 6502 of driver 6500. When tensioningdevice 6400 is assembled to driver 6500 in preparation for use,cylindrical distal portion 6404 of hub 6402 is inserted into proximalcylindrical recess 6504 of handle 6502, o-ring 6002 is compressed bycylindrical recess 6504 thereby creating a friction force therebetweenthat resists relative movement between handle 6502 and hub 6402. Thisfrictional force allows relative movement between handle 6502 and hub6402 when sufficient force is applied. In this manner, during insertionor tensioning of suture, driver 6500 is maintained in its positionrelative to tensioning device 6400 until the surgeon is ready to advancethe anchor to the socket and place the anchor. Applying sufficient forceto handle 6502 allows the surgeon to rotate and distally advance driver6500, the frictional resistance to motion being eliminated when handle6500 has been sufficiently distally advanced so that o-ring 6002 is nolonger positioned within cylindrical recess 6504 of handle 6502.

Unlike previous embodiments in which undesired relative motion betweenthe tensioning device and the driver was prevented by a mechanicalinterlock, system 6000 prevents undesired relative motion by means of africtional force that may be readily overcome by the surgeon to allowanchor placement without removal of a mechanical interlock.Specifically, system 6000 allows rotation of driver 6500 relative totensioning device 6400 when tensioning device 6400 is fully insertedinto driver 6500. In another embodiment of the present inventiondepicted in FIGS. 109 through 111, rotation of the driver relative tothe tensioning device is prevented when the tensioning device is fullyinserted into the driver. Placement system 7000 is identical to system6000 in all aspects of form and function except as specificallydescribed hereafter. Specifically, handle 7502 has formed in itsproximal end channel 7505. Handle 7402 has formed thereon complementaryrib 7405. When tensioning device 7400 is fully inserted into driver 7500rib 7405 is positioned within groove 7505 as depicted in FIG. 111. Themechanical coupling between rib 7405 and channel 7505 prevents rotationof driver 7500 relative to tensioning device 7400 until driver isadvanced distally a sufficient distance to disengage rib 7405 fromchannel 7505.

In yet another embodiment of the present invention, rib 7405 of hub 7502and channel 7505 of hub 7502 are replaced by cams and complementaryfollowers such that rotating the driver handle relative to thetensioning device hub disengages the driver handle from the tensioninghub so as to allow rotational and axial driver motion. Referring now toFIGS. 117 and 118, tensioning device 17400 is identical in all aspectsof form and function to tensioning device 7400 except as specificallydescribed hereafter. Driver 17500 is identical in all aspects of formand function to driver 7500 except as specifically described hereafter.In particular, rib 7405 of hub 7400 is eliminated and replaced with cams17415 on hub 17400. Channel 7505 of handle 7502 is replaced by beveledrecesses 17515 that are complementary to cams 17415 of hub 17400.Proximal cylindrical recess 17504 of driver handle 17502 has a distalportion 17503 and a larger diameter proximal portion 17505. The diameterof distal portion 17503 is such that when cylindrical distal portion17404 of hub 17402 is positioned within cylindrical recess 17505, o-ring17002 is compressed by distal portion 17503 of cylindrical proximalrecess 17504 so as to create a frictional resistance to axial androtational motion of driver 17500 relative to tensioning device 17400.In use, tensioning device 17400 is fully inserted into driver 17400 inthe manner previously herein described with regard to system 1000 (FIGS.12 through 19). O-ring 17002 provides a frictional resistance to motionbetween driver 17500 and tensioning device 17400. Rotating driver handle17502 relative to hub 17402 causes driver 17500 to be displaced axiallydue to cooperative interaction between cams 17415 of hub 17402 andbeveled recesses 17515 of handle 17502. This axial motion causes o-ring17002 to move proximally relative to distal portion 17503 of proximalcylindrical recess 17504 until it is fully proximal of portion 17503whereupon driver 17500 may be freely rotated and moved axially foranchor placement.

When using systems 6000, 7000 and 17000, frictional resistance torelative motion between the tensioning device and driver is maintaineduntil the driver is advanced a predetermined distance relative to thetensioning device. In other embodiments, the frictional resistance torelative motion is maintained throughout the full range of travel of thedriver relative to the tensioning device. An exemplary system 8000having this full range of travel frictional resistance is depicted inFIGS. 112 through 114. Handle 8502 has formed therein cylindrical recess8532 wherein is positioned movable element 8534, compression spring 8536and cap 8530, cap 8530 being affixed to handle 8502 such that spring8536 applies force to movable element 8534. The insertion of tensioningtubular member 8410 into driver tubular member 8510 causes movableelement 8534 to compress spring 8536 so as to create a frictionalresistance to relative movement between driver tubular member 8410 andhandle 8502. This, in turn, provides frictional resistance to motionbetween driver 8500 and tensioning device 8400. This resistance extendsover the full range of travel of driver 8500 relative to tensioningdevice 8400.

Other ways of creating this frictional force are contemplated by thepresent invention, including but not limited to, for example, o-rings orother elastomeric members positioned between elements of driver 8500 andtensioning device 8400, or mechanical interference of metallic orpolymeric elements of driver 8500 and tensioning device 8400. Any systemthat has a non-rotating tensioning device, a driver device positionedcoaxially external to the tensioning device, and a means for creating africtional resistance to relative motion therebetween falls within thescope of this invention.

Other embodiments may forego either or both mechanical interlocking ofthe tensioning device and driver and friction forming means between thedevices. In such cases, unintended relative motion between thetensioning device and driver may be prevented by the surgeon. Forexample, in a preferred embodiment, protrusions formed on the handle ofthe driver provide grasping surfaces for the surgeon's fingers so thatthe driver may be retained in a proximal position on the tensioningdevice until seating of the anchor is required. System 9000 depicted inFIGS. 115 and 116 is identical in all aspects of form and function tosystem 6000 (FIGS. 107 and 108) except as specifically described below.Specifically, in this embodiment, distal cylindrical portion 9404 (notshown in FIGS. 115 and 116) does not have a groove formed therein for ano-ring, and the o-ring is eliminated. Instead, hub 9502 of driver 9500has formed thereon laterally opposed protruding portions 9560.Protruding portions 9560 are configured and positioned so that duringinsertion of the tensioning device distal portion into the socket andpositioning of the graft, the surgeon may retain the driver in itsproximal position on the tensioning device. The surgeon advances thedriver and anchor as in previous embodiments for anchor placement.

It will be understood that while protruding portions 9560 may increasethe ease with which driver 9500 is retained in its proximal position bythe surgeon, they are not required for operability and thus areconsidered to be optional. Thus, any anchor system that includes acannulated implant, a cannulated driver and a non-rotating tensioningmember positioned within the lumen of the cannulated driver, wherein thetensioning device has a distal portion that extends beyond the implantand the driver is axially and rotationally movable relative to thedriver device is considered to be within the scope of this invention.

Anchor placement system 2000, such as depicted in FIGS. 33 through 42,may be utilized in the manner depicted FIGS. 43 through 52, whereinsutures are retained within channel 2446 disposed between distallyextending portions 2444 of distal element 2442 of tensioning device2400, or, alternatively, in the manner depicted in FIGS. 53 through 63,wherein distally extending portions 2444 pierce the graft for insertionof the graft into the socket for anchor placement. In certainembodiments, the distal end of the distal element of the tensioningdevice is optimized for use in one particular manner of introduction oranother. However, in either case, the placement of small diameterimplants may be problematic since the cannulation in the implantnecessarily decreases with the implant diameter.

For example, in the case of cannulated tensioning devices, such as usedin conjunction with system 1000 depicted in FIGS. 13 through 19),wherein sutures are drawn into the lumen of tensioning device 1400, thediameter of the lumen in distal element 1412 limits the number and/orsize of sutures that may be tensioned and affixed using implant 1600.Similarly, when placing small diameter implants using a system thatutilizes a non-cannulated tensioning device (such as device 2000depicted in FIGS. 33 through 42), the diameter of the cannulation in theimplant determines the diameter of distal portion 2442 of insertiondevice 2400. This, in turn, limits the width of channel 2446 in thedistal end of distal portion 2442. Critically, the distally extendingportions 2444 of distal element 2442 must have sufficientcross-sectional area to provide resistance to bending during use. Due tothese limitations, the number and size of sutures that can beaccommodated within channel 2446 is severely limited. Accordingly, thereis a need in the art for an implant placement system in which the numberand/or size of sutures that may be secured with the anchor is notlimited by the diameter of the cannulation in the anchor or thetensioning device.

Such an implant placement system suitable for small diameter anchors isdepicted in FIGS. 119 through 122. Driver 32500 is like driver 2500 inall aspects of form and function except as specifically subsequentlydescribed hereinafter. For example, in this embodiment, handle portion2502 of driver 2500 may be replaced by handle portion 17502 (FIG. 118).Likewise, distal drive portion 32512 of driver 32500 may be configuredto accommodate anchors 32600 of small diameter. That is, thecross-section of distal portion 32514 of distal drive element 32512 maybe reduced and reconfigured for the efficient transmission of torque tosmall diameter anchors, with the cannulation of distal drive element32512 being proportionally reduced.

Like implant 5600 depicted in FIGS. 103 through 106, in which internaldrive features 5602 extend to the distal end of the central lumen ofimplant 5600, internal torque-transmitting features 32602 of implant32600 extend the entire length of the central lumen such that distaltorque-transmitting portion 32514 of distal drive element 32512 suppliestorque to the entire length of implant 5600. If internal drive features32602 extended for only a portion of the length of implant 32600,implant 32600 may fail at the distal end of the portion with theinternal drive features 32602 when the torque supplied to the moredistal portion of implant 32600 exceeds the strength of the implant atthis location.

Tensioning/insertion device 32400, depicted in FIGS. 123 through 130, islike tensioning device 1400 (see, e.g., FIGS. 3 through 9) in allaspects of form and function except as specifically subsequentlydescribed hereinafter. For example, handle portion 1402 may be replacedby handle portion 32402, which has a distal portion like handle portion17402 (FIG. 117) such that handle portion 32402 of the tensioning deviceand handle portion 32502 of driver 32500 may be uncoupled from eachother by rotating handle portion 32502 clockwise (or alternatively,counterclockwise) relative to handle portion 32402. Handle portion 32402preferably has formed thereon flanges 32430 wherein are formed slots32432 configured for the cleating of sutures; such a flange/slotconfiguration is structurally and functionally equivalent to flanges2430 with slots 2432 of tensioning member 2400 depicted in FIGS. 33through 42. Proximal handle portion 32402 may further include cleats32405 formed in its proximal end. Elongate element 30900, which ispositioned within the lumen of cannulated tensioning device 32400,includes a distal portion 30902 that forms a loop, and a pair of looseproximal end portions, 30904 and 30905, that may be removably secured incleats 32405. Pull-tab 30906 may optionally be affixed to first proximalend 30905 of elongate element 30900. In a preferred embodiment, elongateelement 30900 is formed from a super elastic metallic material such as,for instance, nitinol. In other embodiments, elongate element 30900 isformed from a high strength polymeric material.

Implant placement system 30000, depicted as an exploded assembly oftensioning/insertion device 32400, driver 32500 and anchor 32600 in FIG.131, is particularly designed for the placement of small diametercannulated implants in accordance with the present invention. Forexample, the elongate distal portion of tensioning device 32400 may berotatably and slidably positioned within the cannulation (i.e., lumen)of driver 32500. Handles/hubs 32402 and 32502 of tensioning devices32400 and 32500 respectively may then be removably coupled as depictedin FIGS. 117 and 118 and the accompanying description.

Referring now to FIGS. 131 through 136, which depict implant placementsystem 30000 assembled and ready for use, cannulated distal element32412 of tensioning device (acting as inserter) 32400 protrudes distallybeyond the distal drive element 32512 and the anchor 32600 removablymounted thereon. Distal portion 30902 of elongate element 30900 forms aloop adjacent to the distal end of cannulated distal element 32412 oftensioning device 32400. Second proximal end 30904 and first proximalend 30905 of elongate element 30900 may be removably secured (cleated)in slots/cleats 32405, with pull-tab 30906 being affixed to a first end30905 of elongate element 30900.

FIGS. 137 and 138 depict implant placement system 30000 with sutures30930 loaded into distal loop 30902 of elongate element 30900.

The method for placing an implant with implant placement system 30000 isanalogous to method applied to the placement system 2000 depicted inFIGS. 43 through 48 and previously herein described. In fact, themethods are identical except as specifically subsequently describedhereinafter. For example, in the method of use for system 2000, sutures2802 are positioned within gap 2446 between distally extending portions2444 of distal element 2412 (see FIGS. 36 to 38) of tensioning device2400. When using placement system 30000, sutures 30930 are positionedwithin loop 30902 of elongate element 30900. Tensioning of the sutures30930 is accomplished in the same manner as sutures 2802, with thesuture tension/graft position being maintained by cleating of the sutureproximal portions on the handle portion of the tensioning devices,cleats 32432 of handle portion 32402 corresponding to cleats 2432 ofhandle portion 2402 of system 2000 (FIG. 35). Anchor 32600 is placed inthe same manner as anchor 2600. Thereafter, when placing the implantusing system 30000, second proximal end 30904 and first proximal end30905 are released from cleats 32405 of handle portion 32402 oftensioning device 32400. Using pull-tab 30906, elongate element 30900 iswithdrawn in a linear fashion from the device, thereby releasing sutures30930 from the distal end of distal element 32412 of tensioning device32400. Subsequently, tensioning device 32400 and driver 32500 arewithdrawn proximally and sutures 30930 are trimmed to length.

In the aforementioned embodiment, the sutures do not pass through thecannulation. Accordingly, the number and size of sutures that may besecured with implant 3600 are not limited by the size of the cannulationof distal portion 32412 of tensioning device 32400. Thus, when usingimplant placement system 30000, small diameter anchor 32600 may beplaced allowing tissue to be secured with numbers and sizes of suturesnot possible with other anchor systems.

In an alternate embodiment, second end 30904 of elongate element 30900is releasably affixed near the distal end of tensioning device 32400.When anchor placement is complete, second end 30904 is released andelongate element 30900 is withdrawn as previously described herein.

The elements that make up an implant placement system may be formed by avariety of manufacturing processes, all of which include inconsistenciesthat may cause variations in the size of the part produced. As a result,a range is specified for the size of each of the features of thefinished element being produced. So long as the dimensions of all of themeasured features fall within the ranges specified, the element isdeemed acceptable. The tolerances specified depend on the degree ofprecision required for a feature on an element, and also on therepeatability of the process used to form the element. For instance,elongate tubular metallic elements 1410, 1412 and 1510 of implantplacement system 1000 are frequently made by extrusion, a process with ahigh degree of precision. Accordingly, the outer diameter on suchtubular elements may generally be specified to an accuracy of +/−(plusor minus) 0.001 inches, yielding a 0.002 inch range within which thefinished outer diameter must fall. Similarly, the inner diameter of anextruded tube is frequently specified to an accuracy of +/−0.002 inches.Small metallic elements such as driver distal element 1512 that aregenerally formed by machining from bar stock generally have toleranceson their features of +/−0.002 inches. Small polymeric elements likeimplant 1600 of system 1000 formed by injection molding also generallyhave tolerances of +/−0.002 inches on their features.

When designing an assembly, one must consider the range of sizes ofmating features of the elements that make up that assembly. To that end,FIG. 134B shows a cross-section at the location A-A of FIG. 134A. Asinternal drive features 32602 of implant 32600 cannot be produced viamachining, implant 32600 can only be formed by molding. Accordingly,internal drive features 32602 of implant 32600 will have a tolerance of+/−0.002 inches. Dimensions that fall within the 0.004 range for thewidth and height of features 32602 are also acceptable. On the otherhand, distal portion 32514 of distal drive element 32512 will generallybe produced by machining from bar stock and therefore also have a+/−0.002 inches tolerance on the height and width dimensions as iscommon for small machined elements. As a result, a nominal gap of 0.005inches between these complementary features must be specified such thatwhen internal drive features 32602 are at their minimum size (−0.002inches) and distal portion 32514 of distal drive element 32512 is at itsmaximum size (+0.002 inches) there is still a 0.001 inch clearancebetween the elements to allow assembly when the mating features are atthis maximum material condition. The maximum gap between parts willoccur when the mating features of the elements are at their minimummaterial condition, that is, when the height and width of internal drivefeatures 32602 of implant 32600 are at their high limit (+0.002 inches)and the height and width of distal portion 32514 of distal drive element32512 are at their low limit (−0.002 inches). The gap under theseconditions will accordingly be 0.009 inches.

Assemblies must be designed such that complementary (mating) featureswill fit together at maximum material condition, but still function atminimum material condition. In particular, the torque-transmittingfeatures of the implants and associated driver devices of the previouslydescribed embodiments of the present invention must have maximumengagement and maximum torque-transmitting capability at their maximummaterial condition. As the gap between the torque-transmitting featuresis increased, the engagement between the features decreases with anassociated increase in the stress in the material in the engagingregions of the elements, such that the stresses are maximized at theminimum material condition.

When producing systems for the placement of large diameter anchors(e.g., those with diameters greater than three millimeters in diameter),the gap is small compared to the size of the cooperatively actingtorque-transmitting features of the driver distal element and theanchor. Accordingly, the rise in the stress levels as the cooperatingtorque-transmitting features of the implant and driver approach aminimum material condition is minimal. However, when producing systemsfor the placement of small diameter anchors, i.e., those havingdiameters on the order of three millimeters or less, the gap issignificant compared to the size of the cooperatively actingtorque-transmitting features of driver distal element and the implant.For such very small implants, the stress levels in regions of thecooperating torque-transmitting features of the implant and driverincrease as these portions move toward a minimum material condition andmay become sufficiently large to exceed the yield strength of thematerials in these regions. If the yield strength is exceeded, there isa resultant change in the geometry of these features. This may translateinto failure of these features. For example, when placing metal implantsusing a driver with metallic torque-transmitting features, the yieldstrength is sufficiently high to prevent failures, even at minimummaterial conditions. However, when placing a small diameter implantformed of a polymeric material such as, for instance, PEEK, using adriver with metallic torque-transmitting features, the yield strength ofthe torque-transmitting features of the implant may be exceeded duringthreading of the implant into a prepared socket. If this occurs, theanchor is “stripped” and placement of the implant must be aborted.Removal of such an implant can frequently become problematic since,without the ability of the driver to transmit torque to the implant, theimplant cannot be backed out of the socket. Accordingly, the use ofspecial instrumentation for removing the implant is frequently required.

As noted above, high strength ceramic materials such as alumina orzirconia may be formed to complex shapes by a process referred to asCeramic Injection Molding (CIM). In this process, ceramic powder and abinder material are molded to a shape that is subsequently fired in afurnace to eliminate the binder material and sinter the ceramic powder.During this sintering operation the item is reduced in size by twenty tothirty percent and achieves near 100% density with very high dimensionalrepeatability. Ceramic materials which are routinely molded include butare not limited to alumina, zirconia toughened alumina (ZTA) andpartially stabilized zirconia (PSZ). The flexular strength of thesematerials ranges from 55,000 psi to 250,000 psi, far higher than the25,000 psi flexular strength of implantable PEEK material. Asimportantly, ceramic materials do not have a yield point. Deformationdoes not occur until the stress on the material exceeds the failurestress of the material, and the failure stresses of these ceramicmaterials are very high, much higher than the polymeric materials fromwhich implants are commonly formed. These ceramics also have a highdegree of toughness, making them an ideal candidate material forimplants of the present invention.

The CIM process is capable of producing small items with a high degreeof precision and repeatability while faithfully reproducing finefeatures. As such, it is well-suited to forming implants of the presentinvention. Because the material has a very high strength, the wallthicknesses of the anchors may be reduced, thereby allowing an increasein the lumen size of an implant of a given diameter relative to the sameimplant formed from a polymeric material. The manufacturing process andhigh strength ceramic materials are particularly well-suited for smalldiameter implants in they may ensure that the yield strength of thetorque-transmitting features of the implant are not exceeded duringthreading of the implant into a prepared socket.

The ability of the CIM process to produce high strength ceramic objectswith a high degree of precision may also be advantageously applied toforming the distal torque-transmitting element of a driver. For example,distal end drive element 1512 (FIGS. 1 and 2) and distal drive element32512 (FIGS. 120 and 122) each have configurations that may be producedin a high strength ceramic material by the CIM process. As the size ofan implant decreases, the difficulty of machining the associatedmetallic drive element with its torque-transmitting portions increases.Additionally, the yield strength of these metallic drive elements may beinsufficient at minimum material conditions to prevent deformation ofthe drive element when placing an implant. Forming the drive elements ofa high strength ceramic material eliminates this failure mode.

Indeed, the use of high strength ceramic materials may be advantageousfor any threaded implant with internal torque-transmitting features, theimplant being formed by CIM. It is particularly advantageous for smalldiameter implants, e.g., those having diameters on the order of threemillimeters or less.

When a small diameter threaded implant is formed of a high strengthceramic material, the torque-transmitting features of the implantinternal drive features (like features 32602 of implant 32600) may notneed to extend the entire length of the implant. Rather, the strength ofthe ceramic materials may be sufficient to transmit torque through theimplant from torque-transmitting features at the proximal end of theimplant to the more distal portions. Attempting to do this with animplant formed from lower strength material, such as a polymericmaterial, may result in failure of the implant distal to itstorque-transmitting features. Alternatively, the torque-transmittingfeatures may fail, causing the anchor to “strip”.

FIGS. 139 through 143 depict a small diameter implant 41600 formed of ahigh strength ceramic material. Implant 41600 has a central lumen 41604and a threaded outer surface 41610. In the depicted embodiment, thetorque-transmitting feature is a laterally extending channel 41602 thatis located in the proximal end of implant 41600.

FIGS. 144 through 146 depict the distal portion of system 41000configured for the placement of implant 41600. Implant placement system41000 is identical in form and function to system 32000 except asspecifically hereafter described. For example, distal drive element41512 includes a distal portion 41514 having a distal geometry that iscomplementary to torque-transmitting feature 41602 of implant 41600.Although the complementary features are depicted as a pair of taperedribs and mating notches, other quantities, shapes and styles ofcoordinating elements are contemplated by the present invention asdesign alternatives.

The high strength ceramic material from which implant 41600 may beformed allows sufficient torque for reliably threading implant 41600into a prepared socket to be transmitted to the proximal end of implant41600 without failure of the laterally extending channel formingtorque-transmitting feature 41602. FIG. 147 depicts implant 41600positioned on system 41000 in preparation for use. FIG. 148 shows across-sectional view of implant 41600 and placement system 41000.Implant 41600 has a minimum wall thickness 41660 between the centrallumen of implant 41600 and threaded outer surface 41610. Referring nowto FIG. 134B, implant 32600 has a minimum wall thickness 32660 betweentorque-transmitting feature 41602 of the central lumen of implant 32600.Because torque-transmitting feature 41602 is positioned in the proximalend of implant 41600 rather than extending axially within the centrallumen, the minimum wall thickness 41660 is a substantially greaterportion of the diameter of implant 41600 than minimum wall thickness32660 is of the diameter of implant 32600.

FIGS. 149 and 150 depict anchor system 40000 with suture 41830positioned within distal loop 40902 of elongate element 40900 inpreparation for use. System 40000 is used in the same manner as system30000 previously herein described.

In the depicted embodiment, distal portion 41514 of distal drive element41512 forms a tapered laterally extending rib centrally positioned ondistal surface 41513 of drive element 41512. However, as noted above, inother embodiments, distal portion 41514 of distal element 41512 andtorque-transmitting features 41602 of implant 41600 may have othercomplementary forms. For instance, FIGS. 151 through 153 depict analternate embodiment implant 42600 that is identical to implant 41600 inall aspects of form and function except as are hereafter described.Specifically, in this alternative embodiment, torque-transmittingfeatures 42602 are first and second transversely extending channelsformed in the proximal end of implant 42600, the second channel beingperpendicular to the first channel. FIGS. 154 to 156 depict alternateembodiment implant 43600 which is identical to implant 41600 in allaspects of form and function except as is subsequently described, namelytorque-transmitting features 43602 are formed by angularly orientedchannels extending from the proximal surface of implant 43600 to lumen43602. Yet another alternate embodiment 41000 is depicted in FIGS. 147through 160. Implant 44600 is identical in all aspects of form andfunction to implant 41600 except as described hereafter. Specifically,torque-transmitting features 44602 of implant 44600 form a polygonalpocket in the proximal end of implant 44600. Implant 44600 hastorque-transmitting features 44602 that form a pocket with four sides.In other embodiments the pocket formed may have more or fewer sides. Thepolygonal pocket formed by torque-transmitting features 46202 of implant46000 is depicted as having tapered angle 44603. In other embodiments,the polygonal pocket may have a constant cross-section.

Implants 42600, 43600 and 44600 may be introduced by implant placementsystems of the present invention that are alike in all aspects toimplant placement system 41000 except that the distaltorque-transmitting portions of the distal drive elements of therespective implant placement systems may be modified to be complementaryto each corresponding implant, and thereby be configured to transmitoptimal torque thereto.

Indeed, in form, the ceramic implants of the present invention aresimilar to conventional threaded fastening devices such as screws,bolts, and cap screws. Accordingly, any torque-transmitting featuresused by such devices may be applied to ceramic implants as describedherein without departing from the spirit of the present invention.

As previously herein described, for small implants such as 32600, thestress levels in regions of the cooperating torque-transmitting features32602 of implant 32600 and distal portion 32414 of driver distal element32412 increase as these portions move toward a minimum materialcondition and, in certain instances, may become sufficiently large toexceed the yield strength of the materials in these regions. Whentorque-transmitting features like 32602 of lumen 32604 of anchor 32600are so located in the lumen of the implant, the design of the implantwill be strongly affected by the repeatability of the manufacturingprocesses used to form the implant. Considering now FIG. 147, in whichthe engagement between distal portion 41514 of driver distal element41512 and torque-transmitting features 41602 of implant 41600 isdepicted, the stress levels are not strongly affected by variations insize due to inconsistencies in the manufacturing processes used toproduce implant 41600 and distal element 41512. At minimum materialconditions, the channel forming torque-transmitting features 41602 ofimplant 41600 may be enlarged and distal portion 41514 of driver distalelement 41512 may be diminished. There may, however, still besubstantial engagement between the features such that the contactstresses are only minimally increased. Critically, forming thetorque-transmitting features in the proximal end of a ceramic implant ofthe present invention as described for implants 41600, 42600 and 43600makes the implant systems significantly less sensitive to sizevariations due to manufacturing inconsistencies.

FIGS. 161 through 163 depict an alternate embodiment interference-typeanchor 51600 of the present invention formed from a high strengthceramic material by CIM. About the outer surface 51610, a plurality oftapered portions 51610 are formed. Because implant 51600 is drivenaxially into a prepared socket rather than threaded in, proximal-mostsurface 51601 does not have torque-transmitting features formed therein,but rather is planar and designed to receive axial force from thedriver.

Referring now to FIGS. 164 and 165, implant placement system 51000 isconfigured for the placement of implant 51600. Implant system 51000 isidentical in all aspects of form and function to implant system 41000except as specifically described hereafter. System 51000 is configuredto axially drive implant 51600 into a prepared socket by percussiveforce applied to implant 51600 by distal portion 51514 of distal driveelement 51512, the distal-most surface of distal portion 51514 of distaldrive element 51512 having a planar surface. Driver 51500 has a proximalportion configured for receiving impacts from a mallet, the percussiveforce being transmitted by tubular member 51510 to driver distal element51512 and therethrough to implant 51600.

Because the elastic modulus and compressive strength of the ceramicmaterials from which implant 51600 is formed are much higher than thoseof the polymeric materials from which other interference-type implantsare formed, implant 51600 undergoes less compressive deformation duringplacement. Accordingly, the compressive stress applied to a suturetrapped between outer surface 51610 of implant 51600 and the sidewall ofthe socket is increased thereby increasing the resistance to movement ofthe suture.

INDUSTRIAL APPLICABILITY

As noted previously, there is a need in the art for simplified placementsystems and methods for tissue graft anchors by which the surgeon mayintroduce one or more sutures into a prepared socket in the boneytissue, apply tension to the sutures to advance a soft tissue graft to adesired location, and then advance an anchor into the bone whilemaintaining suture tension. The present invention addresses this need byproviding systems and methods for the placement of various implants,especially suture anchors, threaded, knotless or otherwise, that allowthe surgeon to establish the graft position and, while maintaining thatposition, secure the anchor without changing the suture tension orcausing a shift in the graft position and furthermore, when the anchoris threaded, without spinning of the suture. The present invention alsoprovides off-axis socket drills and implant driving devices that enableimplantation in remote and difficult to access boney surfaces usingminimally invasive procedures. The present invention further providesspecialized drivers and tensioning devices suitable for use with smalldiameter implants as well as uniquely constructed knotless anchors andmating drivers formed from high tensile strength materials that areparticularly suited to microsurgery and small space operation. Althoughdescribed in detail with respect to ligament repair, such as repair of atorn rotator cuff, it will be readily apparent to the skilled artisanthat the utility of the present invention extends to other tissues andinjuries.

The disclosure of each publication, patent or patent applicationmentioned in this specification is specifically incorporated byreference herein in its entirety. However, nothing herein is to beconstrued as an admission that the invention is not entitled to antedatesuch disclosure by virtue of prior invention.

The invention has been illustrated by reference to specific examples andpreferred embodiments. However, it should be understood that theinvention is intended not to be limited by the foregoing description,but to be defined by the appended claims and their equivalents.

What is claimed:
 1. An implant placement system for affixing a softtissue graft to a prepared socket in a boney surface via an anchoringimplant, said system comprising: a. a cannulated driver devicecomprising a proximal handle portion having an open proximal end, anelongate tubular distal portion that defines the longitudinal axis ofthe system and includes an open distal end configured to receive saidimplant, and at least one driver lumen extending from said open proximalend to said open distal end; b. an elongate cannulated insertion devicecomprising a proximal hub portion having an open proximal end, a rigiddistal portion that includes an open distal end, and at least oneinsertion lumen extending from open proximal end to said open distalend; and c. an elongate element formed from a suitably elastic metallicor polymeric material and having a first configuration characterized byfirst and second free proximal ends and distal end in the form of asuture capturing loop configured to receive the first ends of one ormore elongate sutures; wherein: i. said insertion device is slidablyreceived within said at least one driver lumen such that said rigiddistal portion extends out of the open distal end of said driver deviceand distally past the distal end of said implant when coupled to saiddriver device; and ii. said elongate element in said first configurationis slidably received within said at least one insertion lumen such thatthe suture capturing loop extends out of and distally past the opendistal end of said insertion device so as to enable said suturecapturing loop to receive said suture first ends.
 2. The implantplacement system of claim 1, wherein said first and second free proximalends of said elongate element extend out of the open proximal end ofsaid insertion device.
 3. The implant placement system of claim 2,wherein the proximal hub portion of said cannulated insertion devicecomprises one or more slots or notches configured to securably receivethe first and second free ends of said elongate element in said firstconfiguration.
 4. The implant placement system of claim 3, wherein saidelongate element further comprises a polymeric pull-tab affixed to saidfirst free proximal end, whereby application of a linear force in theproximal direction to said pull-tab transforms the elongate element intoa second relatively linear configuration that can be withdrawn from saidinsertion lumen via said open proximal end.
 5. The implant placementsystem of claim 4, wherein said elongate element is a nitinol wire. 6.The implant placement system of claim 1, wherein a proximal end of theproximal handle portion of said driver device may be releasably engagedto and disengaged from a distal end of the proximal hub portion of saidinsertion device, such that when said driver device handle portion andsaid insertion device hub portion are engaged, relative rotational andaxial movement between said driver device and insertion device isprecluded and when said driver device handle portion and said insertiondevice hub portion are disengaged, relative rotational and axialmovement between said driver device and insertion device is enabled. 7.The implant placement system of claim 1, wherein the distal end of saiddriver device and a proximal end of said implant are provided withmating features that enable secure attachment of said implant to saiddriver device.
 8. A method for affixing a soft tissue graft to a targetboney surface, the method comprising the steps of: a. providing theimplant placement system of claim 1; b. positioning an implantcomprising a cannulated knotless suture anchor onto the distal end ofsaid driver device; c. providing one or more elongate sutures, each ofwhich has a first free end and a second end attached to said soft tissuegraft; d. threading said first free ends through the suture capturingloop that extends out of and distally past the open distal end of saidinsertion device; e. inserting the distal end of the insertion deviceinto a suitably configured socket disposed in said target boney surface;f. applying tension to the suture to draw the soft tissue graft to adesired position; g. distally advancing said driver device so as todrive the suture anchor in the socket, whereby said implant serves toanchor said soft tissue graft to said target boney surface; h. applyinga linear force in the proximal direction to one of said free proximalends of said elongate element to thereby transform said elongate elementinto a second relatively linear configuration; and i. withdrawing saidelongate element in said second relatively linear from said insertionlumen.
 9. The method of claim 8, wherein, prior to insertion step (e), aproximal end of the proximal handle portion of said driver device isengaged to a distal end of the proximal hub portion of said insertiondevice so as to preclude relative rotational and axial movement betweensaid driver device and insertion device.
 10. The method of claim 9,wherein said driver device handle portion and said insertion device hubportion are disengaged prior to step (g).
 11. An implant placementsystem for affixing a soft tissue graft to a prepared socket in a boneysurface via an anchoring implant, said system comprising: a. acannulated knotless suture anchor comprising a relatively cylindricalbody having: i. a proximal surface including an open proximal end and adistal surface including an open distal end; ii. an inner surfacecomprising a tubular lumen that extends from said open proximal end tosaid open distal end and defines the longitudinal axis of the body; andiii. an outer surface provided with socket-engaging features; wherein:i. said proximal surface is characterized by one or moretorque-receiving recesses configured to mate with and engage one or morecorresponding torque-transmitting projections disposed on a distal endof a driver device; and ii. said suture anchor is fabricated from a hightensile strength ceramic material; b. a cannulated driver devicecomprising a proximal handle portion having an open proximal end, anelongate tubular distal portion that defines the longitudinal axis ofthe system and includes an open distal end configured to receive saidcannulated knotless suture anchor, and at least one driver lumenextending from said open proximal end to said open distal end, whereinthe distal end of said driver device and the proximal end of saidcannulated knotless suture anchor are provided with mating features thatenable secure attachment of said anchor to said driver device; and c. anelongate insertion device having a proximal hub portion and a rigiddistal portion configured to receive the first ends of one or moreelongate sutures, wherein said insertion device is slidably receivedwithin said at least one driver lumen of said driver device.
 12. Theimplant placement system of claim 11, wherein said cannulated knotlesssuture anchor is fabricated from a high tensile strength ceramicmaterial selected from the group consisting of alumina and zirconia. 13.The implant placement system of claim 11, wherein both the cannulatedknotless suture anchor and at least the mating features of saidcannulated driver device are shaped by Ceramic Injection Molding (CIM).14. The implant placement system of claim 11, wherein said matingfeatures comprise (a) one or more torque-transmitting projectionsdisposed on the distal end of said cannulated driver device that matewith and engage (b) one or more corresponding torque-receiving recessesdisposed in the proximal surface of said cannulated knotless sutureanchor.
 15. The implant placement system of claim 14, wherein the one ormore torque-receiving recesses comprises a single transversely extendingchannel that bisects said proximal surface and extends from saidproximal surface into a proximal region of said outer surface, forming apair wedge-shaped notches disposed on opposite sides of the proximal endof said anchor and the corresponding one or more torque-transmittingprojections comprise a pair of tapered ribs disposed on opposite sidesof the distal end of said driver device.
 16. The implant placementsystem of claim 14, wherein said one or more torque-receiving recessescomprises a first transversely extending channel that bisects saidproximal surface and a second transversely extending channelperpendicular to said first channel and the corresponding one or moretorque-transmitting projections comprise a set of ribs arrayed in acruciform.
 17. The implant placement system of claim 14, wherein saidone or more torque-receiving recesses comprises a single polygonalpocket that extends into a proximal portion of said tubular lumen andthe one or more torque-transmitting projections comprise a matingpolygonal protrusion.
 18. The implant placement system of claim 11,wherein said cannulated knotless suture anchor comprises an interferenceplug-type anchor.
 19. The implant placement system of claim 11, whereinsaid suture anchor comprises a threaded anchor.
 20. The implantplacement system of claim 11, wherein a proximal end of the proximalhandle portion of said driver device may be releasably engaged to anddisengaged from a distal end of the proximal hub portion of saidinsertion device, such that when said driver device handle portion andsaid insertion device hub portion are engaged, relative rotational andaxial movement between said driver device and insertion device isprecluded and when said driver device handle portion and said insertiondevice hub portion are disengaged, relative rotational and axialmovement between said driver device and insertion device is enabled. 21.The implant placement system of claim 11, wherein said system furtherincludes an elongate element formed from a suitably elastic metallic orpolymeric material and having a first configuration characterized byfirst and second free proximal ends and distal end in the form of asuture capturing loop configured to receive the first ends of one ormore elongate sutures; wherein: i. said insertion device is slidablyreceived within said at least one driver lumen such that rigid distalportion extends out of the open distal end of said driver device anddistally past the distal end of said suture anchor when coupled to saiddriver device; and ii. said elongate element in said first configurationis slidably received within said at least one insertion lumen such thatthe suture capturing loop extends out of and distally past the opendistal end of said insertion device so as to enable said suturecapturing loop to receive said suture first ends.
 22. The implantplacement system of claim 21, wherein said first and second freeproximal ends of said elongate element extend out of the open proximalend of said insertion device.
 23. The implant placement system of claim22, wherein the proximal hub portion of said cannulated insertion devicecomprises one or more slots or notches configured to securably receivethe first and second free ends of said elongate element in said firstconfiguration.
 24. The implant placement system of claim 23, whereinsaid elongate element further comprises a polymeric pull-tab affixed tosaid first free proximal end, whereby application of a linear force inthe proximal direction to said pull-tab transforms the elongate elementinto a second relatively linear configuration that can be withdrawn fromsaid insertion lumen via said open proximal end.
 25. The implantplacement system of claim 24, wherein said elongate element is a nitinolwire.